[14.0][IMP] web_company_color: UI improvements

[ajaniszewska-dev]

1. add field to control input bg color : before this change "button background color" was changing not only button's bg color but also input fields bg color.

[ajaniszewska-dev]

@Tardo could you review? :pray:

[Tardo]

@JuMiSanAr

Looks good. However, I'm assuming the previous color system was intended as is and someone might want to keep it, maybe this should go into its own module?

Yes, it may be a problem... but for me the previous color was not correct either. I don't know to what extent the previous color matched the real color.

Can always do a migration script and set the color of the new field to the value that the operation gave: lighten(%(color_button_bg)s, 10%)