Feature request: override local cache logic

I would love to have a local cache that does not compare mtimes of the file in the local cache and remote bucket. I understand that this is not safe, but I'm working with a lot of immutable files.

This kind of cache might not be important to other cloudpathlib users, so the actual feature request is to allow overriding of the cache logic. I skimmed the code and did not find a way to do this, but it is possible that I missed it.

If you are interested, I could probably contribute this myself.