ValueOnly mode could report some UCI info

[dje-dev]

Currently ValueOnly mode returns a UCI info string which only has depth. However it would be meaningful and useful to see value score, etc. Also this would fix the problem that some tournament managers support adjudication by mutual agreement of obvious win/loss and therefore need to see this score from both engines.

Currently output looks like this:

setoption name ValueOnly value true
ucinewgame
go nodes 1
info depth 1
bestmove e2e4

but it could instead be similar to a policy-only search such as:

info depth 1 seldepth 1 time 12 nodes 1 score cp 7 tbhits 0 pv e2e4