ColorEdit: Fix multiple issues. (#4014)

* Change g.ColorEditLastColor type to ImU32 and store RGB color value.
  - Fixes inability to change hue when saturation is 0. (#4014)
  - Fixes edgecases where lossy color conversion prevent restoration of hue/saturation.
  - Fixes hue value jitter when modifying color using SV square.
* Fix hue resetting to 0 when it is set to 255 by explicitly restoring hue if it is 0 and previous value was 1.
* Further reduce hue jitter by restoring hue when color is modified using SV square.
4 files changed