Flag sprites was not updated after renaming canada.gif back to ca.gif and "multi-language" was missing
In #24477 the canada / catalonian flags were exchanged and later rolled-back. But the sprite was not updated.
While updating the flags sprite I also noticed that the "multiple.gif" which represent "multiple languages" was not added as a sprite before. And also that it was called "multi-language.gif" before.
So this issue should fix these things:
1) new sprite containing the correct "ca" = canada and "catalonia" = Catalonian flag
2) using the existing array of "flags" (not languageCodes!!) to also make the sprites available, instead of listing them one by one in ext_tables.php.
3) update the Upgrade Wizard which should also convert the old-school "multi-languages.gif" to "multiple" sprite.
(issue imported from #M17316)