Add option to configure START+SELECT hold duration to exit

[wcko87]

START+SELECT Exit Delay can be set to 0ms for instant exit from play.
(I think the current press duration for exit is too long)

Default value is 1000ms (current beatoraja exit delay)

exit_delay.mp4

I may need help with the Japanese translation of the option.
English: START+SELECT Exit Delay
Japanese: START+SELECT終了まで時間

translation is difficult because I want to keep the option name short