Introduced the notion of a RandomAccessFilter that guarantees to produce a FixedBitSet.

Nested and parent/child rely on the fact that type filters produce a FixedBitSet, the RandomAccessFilter does this. By moving away from filter cache this filters will also never be evicted because of LRU reasons, which is what is desired for nested and parent/child.

Also if nested and parent/child is configured the type filters are eagerly loaded by default.

PR for #7031
Does it work? (given that `loadedFilters` uses a Key object as key while you are invalidating with a reader core key here?)