Before attempting to fix issues with invalid selections reaching
gameplay, I needed to do a pass of the song select class as selection
logic was already more complex than I'd hope.
All operations now go through a single flow (`SelectAndRun`) when
leaving the song select screen in a "success" state.
By falling back to the default of 40% of track duration in such cases.
Also added a safety for the restart point exceeding acceptable bounds in
case of a non-zero offset.
Closes https://github.com/ppy/osu/issues/33308.