Update Color Dialog text to 2.99
- Correct order of mode selectors.
- Split mode selectors and other UI elements into two separate lists.
- Remove irrelevant and confusing comparison to toolbox FG/BG tool.
- Explain things according to where they are in the UI (move last used colors to bottom).
- Move GIMP selector mode screenshot down to the GIMP selector mode section where it belongs.
- Remove "symbolized by a brush" as it depends on the icon theme.
- Use consistent naming style for figure titles.
- Use consistent naming for stuff: Rename Triangle to Wheel. Rename Eyedropper to Color Picker.