Fix StateMachine process when transition to end & optimize StringName

[TokageItLab]

• Fixes RootStateMachine does not calculate the remaining time until the transiton to End state actually occurs #79537
• Fixes To detect the end of the state machine, one frame is required after moving to the End state #94280

Perhaps the main cause of the one frame delay is due to pending requests, so make it so that a reset request is not sent on the transition to End.

Also, if the Transition knows that the next State is End, calculate the remaining time. If there is a fade outside of the StateMachine, the StateMachine should now fade out properly as long as the length of the animation before the EndState is longer than the fade time.

Moreover, replace String comparisons with static StringName for performance.

[fire]

This makes sense. Need to watch we're only creating / setting the stringname rarely.

[akien-mga]

Thanks!