Splits editor

[1nf3rna]

Current issues:

1. Changes to the splits info gets overwritten. Likely just need to figure out an object update issue. Should probably write changes to a temporary object first anyway.
2. LSC seems to be missing a way to clear the PB
3. Times are in whole nanoseconds currently.
4. Table doesn't seem to have a vertical end, so long split lists might not work right
5. Can't figure out how to convert from livesplit images to egui images
6. Segment times only seem to be available from segment history so split times might have to be calculated...