Recycle memory of LRU cache for offsets and symlinks

ccache does not recycles memory of expired items, we wan't to implement this.

• reconsider expiration times for these caches.

The following discussion from !364 (merged) should be addressed:

• @vshushlin started a discussion: (+5 comments)

  Question: Do we really need an expiration mechanism for these caches?

  Since we cache these values within namespace based on zip archive "object id" and underlying structure can't change with time I assume these offsets and links will be valid forever.

  I think ccache doesn't support "infinite" expiration time, but we can just use big value, like 24 hours or something.

  WDYT?