Cached methods don't account for language switching

[Sibert-Aerts]

(To preface this, I found this fork after using the original wikipedia library for far too long and getting fed up with its shortcomings, and I'm very happy to have found a kept-up fork that seems to address all the problems I was having!)

As the title says, calling e.g. .search with the same query after switching languages still returns the old language's search results.

I believe in the old library switching languages would just wipe all caches (what exactly was being cached I don't recall...)

For my se case I tend to switch languages often enough that this bug could cause problems. An optimal solution for my use would be accounting for the language as part of the cache key, but from how I see the memoization is set up that wouldn't be a trivial fix.

The issue can be circumvented from my end by just creating a different MediaWikiAPI instance per language, so it's not actually preventing me from using the library.