Improve UCI parser to better comply with the spec

[brunocodutra]

fastchess --compliance target/bin/cinder-v0.1.2-linux-native 
 Passed Step 1: Start the engine
 Passed Step 2: Check if engine is ready
 Passed Step 3: Check id name
 Passed Step 4: Check id author
 Passed Step 5: Send ucinewgame
 Passed Step 6: Set position to startpos
 Passed Step 7: Check if engine is ready after startpos
 Passed Step 8: Set position to fen
 Passed Step 9: Check if engine is ready after fen
 Passed Step 10: Send go wtime 100
 Passed Step 11: Read bestmove
 Passed Step 12: Check if engine prints an info line
 Passed Step 13: Verify info line contains score
 Passed Step 14: Set position to black to move
 Passed Step 15: Send go btime 100
 Passed Step 16: Read bestmove after go btime 100
 Passed Step 17: Check if engine prints an info line after go btime 100
 Passed Step 18: Check if engine prints an info line with the score after go btime 100
 Passed Step 19: Send go wtime 100 winc 100 btime 100 binc 100
 Passed Step 20: Read bestmove after go wtime 100 winc 100 btime 100 binc 100
 Passed Step 21: Check if engine prints an info line after go wtime 100 winc 100
 Passed Step 22: Check if engine prints an info line with the score after go wtime 100 winc 100
 Passed Step 23: Send go btime 100 binc 100 wtime 100 winc 100
 Passed Step 24: Read bestmove after go btime 100 binc 100 wtime 100 winc 100
 Passed Step 25: Check if engine prints an info line after go btime 100 binc 100
 Passed Step 26: Check if engine prints an info line with the score after go btime 100 binc 100
 Passed Step 27: Check if engine prints an info line after go btime 100 binc 100
 Passed Step 28: Send ucinewgame
 Passed Step 29: Set position to startpos
 Passed Step 30: Send go wtime 100
 Passed Step 31: Read bestmove after go wtime 100 btime 100
 Passed Step 32: Set position to startpos moves e2e4 e7e5
 Passed Step 33: Send go wtime 100 btime 100
 Passed Step 34: Read bestmove after position startpos moves e2e4 e7e5
Engine passed all compliance checks.