[fix] qwant - API error::locale must be one ..

The request function should not request a language (aka locale) that is not
supported by qwant. Select a locale like zh-TW ends in qwant's API error:

  ERROR searx.engines.qwant news: exception : \
  API error::locale must be one of the following values: \
    en_gb, en_ie, en_us, en_ca, en_my, en_au, en_nz, de_de, de_ch, de_at, fr_fr, \
    fr_be, fr_ch, fr_ca, fr_ad, fc_ca, co_fr, es_es, es_ar, es_cl, es_co, es_mx, \
    es_pe, es_ad, ca_es, ca_ad, ca_fr, eu_es, eu_fr, it_it, it_ch, pt_pt, pt_ad, \
    nl_be, nl_nl

The existing searx.utils.match_language function is unsuitable for this purpose,
it is replaced by function searx.locales.get_engine_locale that is based on the
methods from the babel package.

The quant's _fetch_supported_languages function has been revised to filter out
languages 8aka locales) not supported by qwant.

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

1 files changed, 149 insertions, 164 deletions

diff --git a/searx/data/engines_languages.json b/searx/data/engines_languages.json
index 1d4d9b2e3..3ee6fad79 100644
--- a/searx/data/engines_languages.json
+++ b/searx/data/engines_languages.json
@@ -1396,170 +1396,155 @@
     "sv",
     "zh"
   ],
-  "qwant": [
-    "bg-BG",
-    "ca-ES",
-    "cs-CZ",
-    "da-DK",
-    "de-AT",
-    "de-CH",
-    "de-DE",
-    "el-GR",
-    "en-AU",
-    "en-CA",
-    "en-GB",
-    "en-IE",
-    "en-MY",
-    "en-NZ",
-    "en-US",
-    "es-AR",
-    "es-CL",
-    "es-ES",
-    "es-MX",
-    "et-EE",
-    "fi-FI",
-    "fr-BE",
-    "fr-CA",
-    "fr-CH",
-    "fr-FR",
-    "hu-HU",
-    "it-CH",
-    "it-IT",
-    "ko-KR",
-    "nb-NO",
-    "nl-BE",
-    "nl-NL",
-    "pl-PL",
-    "pt-PT",
-    "ro-RO",
-    "sv-SE",
-    "th-TH",
-    "zh-CN",
-    "zh-HK"
-  ],
-  "qwant images": [
-    "bg-BG",
-    "ca-ES",
-    "cs-CZ",
-    "da-DK",
-    "de-AT",
-    "de-CH",
-    "de-DE",
-    "el-GR",
-    "en-AU",
-    "en-CA",
-    "en-GB",
-    "en-IE",
-    "en-MY",
-    "en-NZ",
-    "en-US",
-    "es-AR",
-    "es-CL",
-    "es-ES",
-    "es-MX",
-    "et-EE",
-    "fi-FI",
-    "fr-BE",
-    "fr-CA",
-    "fr-CH",
-    "fr-FR",
-    "hu-HU",
-    "it-CH",
-    "it-IT",
-    "ko-KR",
-    "nb-NO",
-    "nl-BE",
-    "nl-NL",
-    "pl-PL",
-    "pt-PT",
-    "ro-RO",
-    "sv-SE",
-    "th-TH",
-    "zh-CN",
-    "zh-HK"
-  ],
-  "qwant news": [
-    "bg-BG",
-    "ca-ES",
-    "cs-CZ",
-    "da-DK",
-    "de-AT",
-    "de-CH",
-    "de-DE",
-    "el-GR",
-    "en-AU",
-    "en-CA",
-    "en-GB",
-    "en-IE",
-    "en-MY",
-    "en-NZ",
-    "en-US",
-    "es-AR",
-    "es-CL",
-    "es-ES",
-    "es-MX",
-    "et-EE",
-    "fi-FI",
-    "fr-BE",
-    "fr-CA",
-    "fr-CH",
-    "fr-FR",
-    "hu-HU",
-    "it-CH",
-    "it-IT",
-    "ko-KR",
-    "nb-NO",
-    "nl-BE",
-    "nl-NL",
-    "pl-PL",
-    "pt-PT",
-    "ro-RO",
-    "sv-SE",
-    "th-TH",
-    "zh-CN",
-    "zh-HK"
-  ],
-  "qwant videos": [
-    "bg-BG",
-    "ca-ES",
-    "cs-CZ",
-    "da-DK",
-    "de-AT",
-    "de-CH",
-    "de-DE",
-    "el-GR",
-    "en-AU",
-    "en-CA",
-    "en-GB",
-    "en-IE",
-    "en-MY",
-    "en-NZ",
-    "en-US",
-    "es-AR",
-    "es-CL",
-    "es-ES",
-    "es-MX",
-    "et-EE",
-    "fi-FI",
-    "fr-BE",
-    "fr-CA",
-    "fr-CH",
-    "fr-FR",
-    "hu-HU",
-    "it-CH",
-    "it-IT",
-    "ko-KR",
-    "nb-NO",
-    "nl-BE",
-    "nl-NL",
-    "pl-PL",
-    "pt-PT",
-    "ro-RO",
-    "sv-SE",
-    "th-TH",
-    "zh-CN",
-    "zh-HK"
-  ],
+  "qwant": {
+    "bg-BG": "bg_BG",
+    "ca-ES": "ca_ES",
+    "cs-CZ": "cs_CZ",
+    "da-DK": "da_DK",
+    "de-AT": "de_AT",
+    "de-CH": "de_CH",
+    "de-DE": "de_DE",
+    "el-GR": "el_GR",
+    "en-AU": "en_AU",
+    "en-CA": "en_CA",
+    "en-GB": "en_GB",
+    "en-IE": "en_IE",
+    "en-MY": "en_MY",
+    "en-NZ": "en_NZ",
+    "en-US": "en_US",
+    "es-AR": "es_AR",
+    "es-CL": "es_CL",
+    "es-ES": "es_ES",
+    "es-MX": "es_MX",
+    "et-EE": "et_EE",
+    "fi-FI": "fi_FI",
+    "fr-BE": "fr_BE",
+    "fr-CA": "fr_CA",
+    "fr-CH": "fr_CH",
+    "fr-FR": "fr_FR",
+    "hu-HU": "hu_HU",
+    "it-CH": "it_CH",
+    "it-IT": "it_IT",
+    "ko-KR": "ko_KR",
+    "nb-NO": "nb_NO",
+    "nl-BE": "nl_BE",
+    "nl-NL": "nl_NL",
+    "pl-PL": "pl_PL",
+    "pt-PT": "pt_PT",
+    "ro-RO": "ro_RO",
+    "sv-SE": "sv_SE",
+    "th-TH": "th_TH",
+    "zh-CN": "zh_CN",
+    "zh-HK": "zh_HK"
+  },
+  "qwant images": {
+    "bg-BG": "bg_BG",
+    "ca-ES": "ca_ES",
+    "cs-CZ": "cs_CZ",
+    "da-DK": "da_DK",
+    "de-AT": "de_AT",
+    "de-CH": "de_CH",
+    "de-DE": "de_DE",
+    "el-GR": "el_GR",
+    "en-AU": "en_AU",
+    "en-CA": "en_CA",
+    "en-GB": "en_GB",
+    "en-IE": "en_IE",
+    "en-MY": "en_MY",
+    "en-NZ": "en_NZ",
+    "en-US": "en_US",
+    "es-AR": "es_AR",
+    "es-CL": "es_CL",
+    "es-ES": "es_ES",
+    "es-MX": "es_MX",
+    "et-EE": "et_EE",
+    "fi-FI": "fi_FI",
+    "fr-BE": "fr_BE",
+    "fr-CA": "fr_CA",
+    "fr-CH": "fr_CH",
+    "fr-FR": "fr_FR",
+    "hu-HU": "hu_HU",
+    "it-CH": "it_CH",
+    "it-IT": "it_IT",
+    "ko-KR": "ko_KR",
+    "nb-NO": "nb_NO",
+    "nl-BE": "nl_BE",
+    "nl-NL": "nl_NL",
+    "pl-PL": "pl_PL",
+    "pt-PT": "pt_PT",
+    "ro-RO": "ro_RO",
+    "sv-SE": "sv_SE",
+    "th-TH": "th_TH",
+    "zh-CN": "zh_CN",
+    "zh-HK": "zh_HK"
+  },
+  "qwant news": {
+    "ca-ES": "ca_ES",
+    "de-AT": "de_AT",
+    "de-CH": "de_CH",
+    "de-DE": "de_DE",
+    "en-AU": "en_AU",
+    "en-CA": "en_CA",
+    "en-GB": "en_GB",
+    "en-IE": "en_IE",
+    "en-MY": "en_MY",
+    "en-NZ": "en_NZ",
+    "en-US": "en_US",
+    "es-AR": "es_AR",
+    "es-CL": "es_CL",
+    "es-ES": "es_ES",
+    "es-MX": "es_MX",
+    "fr-BE": "fr_BE",
+    "fr-CA": "fr_CA",
+    "fr-CH": "fr_CH",
+    "fr-FR": "fr_FR",
+    "it-CH": "it_CH",
+    "it-IT": "it_IT",
+    "nl-BE": "nl_BE",
+    "nl-NL": "nl_NL",
+    "pt-PT": "pt_PT"
+  },
+  "qwant videos": {
+    "bg-BG": "bg_BG",
+    "ca-ES": "ca_ES",
+    "cs-CZ": "cs_CZ",
+    "da-DK": "da_DK",
+    "de-AT": "de_AT",
+    "de-CH": "de_CH",
+    "de-DE": "de_DE",
+    "el-GR": "el_GR",
+    "en-AU": "en_AU",
+    "en-CA": "en_CA",
+    "en-GB": "en_GB",
+    "en-IE": "en_IE",
+    "en-MY": "en_MY",
+    "en-NZ": "en_NZ",
+    "en-US": "en_US",
+    "es-AR": "es_AR",
+    "es-CL": "es_CL",
+    "es-ES": "es_ES",
+    "es-MX": "es_MX",
+    "et-EE": "et_EE",
+    "fi-FI": "fi_FI",
+    "fr-BE": "fr_BE",
+    "fr-CA": "fr_CA",
+    "fr-CH": "fr_CH",
+    "fr-FR": "fr_FR",
+    "hu-HU": "hu_HU",
+    "it-CH": "it_CH",
+    "it-IT": "it_IT",
+    "ko-KR": "ko_KR",
+    "nb-NO": "nb_NO",
+    "nl-BE": "nl_BE",
+    "nl-NL": "nl_NL",
+    "pl-PL": "pl_PL",
+    "pt-PT": "pt_PT",
+    "ro-RO": "ro_RO",
+    "sv-SE": "sv_SE",
+    "th-TH": "th_TH",
+    "zh-CN": "zh_CN",
+    "zh-HK": "zh_HK"
+  },
   "startpage": {
     "af": {
       "alias": "afrikaans"