Fix issue with cache param map leaks, add fuzzy remove tests

Param maps weren't being properly cloned before being used as the keys,
meaning that the key could be modified after being used. This led to
some weird behaviour where keys would duplicate themselves.

Additionally added some fuzzy key removal tests to validate the
functionality as there were some issues in a downstream project that
used the call. There were no issues in code for fuzzyRemove, so it was
left unchanged.