/client texcache Command early implementation

[minecraft8997]

Howdy! This is my attempt to implement a client command that would tell the user where the cached texture pack (and whether it is at all) located on their storage. However I was very unsure whether it was appropriate to make IsCached function non-static and accepting a new parameter. I renamed it to TexturePack_IsCached leaving the original static IsCached method for compatibility purposes.

[UnknownShadow200]

I saw that your pr was not merged. I have an active repo that accepts multiple pull requests. I'm sure your commit will be in there.

I do accept pull requests. I didn't merge because I didn't feel that it was the right approach