Updates hex color label to entry, adds rgb entry option and cleans up the code a bit and adds docstrings to the functions along with comments.

[marini-pietro]

Needeed this kind of widget for a personal open source project but it missed a few features I was looking for, so I figured out I should add them.
Now the hex color is an editable entry, there is an option to add rgb entries to the widget and the target automatically updates its position (still in beta, cannot find all colors accurately).
(Editing the hex color entry automatically updates the rgb entries and viceversa).
Cleaned up the code a bit and added comments and docstrings to the functions.
For now I've edited ctk_color_picker_widget file because it is the one I needed for my project.