Support `UCI_ShowCurrLine`, `UCI_ShowRefutations` options

[benthevining]

Discussed in #509

^{Originally posted by benthevining March 14, 2026}

• UCI_ShowCurrLine, type check, should be false by default, the engine can show the current line it is calculating. See info currline above.
• UCI_ShowRefutations, type check, should be false by default, the engine can show a move and its refutation in a line. see info refutations above.