Add support for changing the colour of the button when hovering and clicking

[ufgo]

It is necessary to add the ability to specify the colour of the button when hovering and clicking, similar to already implemented parameters such as HOVER_SCALE. This will allow to flexibly set visual behaviour of buttons in style through parameters.

Logic implementation:
- When a button is hovered over, its colour should change according to HOVER_COLOR.
- When pressed - according to self.start_colour.
- If no parameters are set, use the current colour without changes.

Compatibility support:
New parameters should not affect existing functionality unless specified.

[Insality]

Isn't simpler will be implement such styling in your custom button and then create that button instead all default one

Or you will just to customize this through the styles? I'm concerning about adding kind of detailed stuff

But probably I will add more generic to be able do that through styles, so you can save you params in kind of style.on_init and use them in a relative callbacks