High Score intials entry - refactor

[MarkInc666]

The high score initials entry times out too quickly.

• It uses a single value for timeout.

I think the _ask_player_for_initials routine needs some changes.
Currently it allows 'enter_initials_timeout' seconds (default 20s) for all three letters.
This timer should only run when there is no user input and should be reset when each letter is selected.