Remember last color_mode and picker_shape in ColorPickers in the editor

[TheSofox]

Fixes #86063

Now when using ColorPicker in the Editor, it will always use the last color_mode (RGB/HSV/etc) and picker_shape (Rectangle/Wheel/Circle/etc.) that the user chose in ANY ColorPicker. (eg. If you chose HSV while in the Picker for a Sprite's modulate colour, then HSV will be chosen if you then open the Picker for the Color of a ColorRect)

This is a Project specific setting. The first time the Project is started, it will use EditorSettings for the default of these two values. Any changes will persist across all Pickers in the project and across closing and opening the project again (values saved to hard drive). It will NOT affect Pickers in exported running projects, this is Editor only.

[YuriSizov]

Note that our preferred commit message format is to start with a verb and then follow up with the body of the change. Please amend your commit message to be similar to what the title of the PR is right now.

[TheSofox]

Amended commit message. I'll try to remember to start commit messages with a verb from now on.

[KoBeWi]

I see 2 concerns here:

• Users might get confused that changing editor setting has no effect. This can be solved with documentation probably, and I doubt someone will change this more than once anyway
• When opening color picker, the setting is immediately written to the file, because editor calls set_color_mode() and set_picker_shape(). This could be solved with an intermediate method called when changing the modes manually (i.e. not from code)

The implementation looks good though, so the above remarks can be addressed later.

[YuriSizov]

Thanks!