Add UI

[optimus-code]

Add a UI window to represent the LegacyFlavourConfig class settings.

• [ ] SVG icons for LegacyFlavour
• [x] Checkboxes for bool properties
• [x] Sliders for 0-1 decimal values
• [x] Colour mode selector based on enum
• [x] Add a tab for each colour mode
• [x] Configure each mode tab to show colour pickers with labels for all the options,
• [x] Utility/functional icon buttons for toggling bool functions like whiteness, custom zone colouring