Rework cache to use inline cache

[vchuravy]

We currently put entries into the cache under two different keys.

• objectid(src), tls_world, cfg
• ci, cfg

The first is meant as a fast hit in scenarios where the current world-age is not changing.
If we follow Julia Base, we could instead replace the first with a linear search over a small
number of entries.

By storing the ci as a field in the cache struct we quickly check if the cache is still valid,
currently when the tls_world changes we fall-back to the slower cache check.

I was thinking of adding something similar to Enzyme.
This is an API breakage though. So I am not convinced it is worth it right now.

[vchuravy]

This would be the API breakage. We need to change this to AbstractDict{<:Any, CacheEntry}{V}} or take V as a separate parameter.