Recycler: better lifecycle control for pooled instances (#5214)

- introduce additional destroy() callback that allows better control
over internals of recycled data
- introduced AbstractRecyclerC as superclass for Recycler factories
(Adrien) with empty destroy() by default
- added tests for destroy()
- cleaned up Recycler tests (reduce copy&paste)
Implement BlendedTermQuery#extractTerms to support highlighing.

some of the highlighters require term extraction to be implemented in
order to work. BlendedTermQuery doesn't implement the trivial extraction.

Closes #5246
Add coming 0.90.12 version to the constants