Introduce node type flags in TT Entry

This will be used to verify node type before
to return a TT value.

Currently only in search, not in qsearch.

Also a bit of renaming while there.

No functional change.
Use node type to control TT cut-off

For an All node don't use a hash value that is flagged as BOUND_UPPER_CUT.
For a  Cut node don't use a hash value that is flagged as BOUND_LOWER_ALL.

bench: 4547569
Always accept TT value in a cut node

Instead for All nodes, accept fail lows only if not
from a previous cut node.

And accept fail-high only if from a previous All node-

bench: 4247128
Another TT cut/all tweak

bench: 3759987
Merge remote-tracking branch 'upstream/tt_cut_all' into static_cutall