feat: query cache provider (#476)

* feat: query cache provider

the query cache now comes from a context, meaning users can easily override and control the cache being used inside their application

* fix: track multiple query caches

this commit does the follwing:
track all active query caches added via the provider, handles mounting/unmounting
if creating a cache, ensure we only do it once
when unmounting an internally-created cache, make sure to clear it first
setFocusHandler now loops through all of the currently-active caches

* test: add in-depth tests around query cache providers

* style: format touched files

* fixup! style: format touched files

* docs: correct readme description

Co-authored-by: Tanner Linsley <tannerlinsley@gmail.com>

Co-authored-by: Jack Ellis <jack.ellis@godaddy.com>
Co-authored-by: Tanner Linsley <tannerlinsley@gmail.com>