Add match_language function in utils to match any user given
language code with a list of engine's supported languages.

Also add language_aliases dict on each engine to translate
standard language codes into the custom codes used by the engine.

and refactor method to make it testable without making requests

utils/fetch_languages.py gets languages supported by each engine and
generates engines_languages.json with each engine's supported language.

also minor changes in attributes and images from wikidata

disambiguation and tags are in local language

TOFIX:
    needs to query the api every time to know each label's name

creates simple multilingual infobox using wikipedia's api

For DoB and DoD, wikipedia use a non standard ISO format, not easily readable.
Now the date is displayed in an human readable form, using the language setting as locale if available. If not, it uses the default locale.

[enh] infoboxes : if the result doesn't contain anything except one link, use the normal result template