mediawiki.api: Use action=query&meta=tokens instead of action=tokens

api.php?action=query&meta=tokens has different token types.
A mapping keeps the JavaScript API stable.

Bug: 72094
Change-Id: I429b609b626af35ae0abcdf6f1c13e8afb6503b9
Merge "mediawiki.api: Use action=query&meta=tokens instead of action=tokens"