When trying to charge the assetbundle the theme-color("primary") function
is not found what causes problems when trying to set the default values.
With this changes the default value is the value set on ad9f8fae71/addons/web/static/src/scss/primary_variables.scss (L55)
this change avoid the problems and the module works fine.
Addapted too the class for required fields.
Before it didn't work if just a color was set because it couldn't find "color_navbar_bg_hover".
Moreover, in odoo enterprise the navbar background color only worked for the main app menu,
now it works for both main app menu and the navbar of the apps.
If we change something with base.document.layout wizard, this will launch the colors computing even without changing the logo. This procedure will change the value of the colors if they were set by hand.
This change forces the user to press a button to recompute the colors and avoid possible undesired changes.
TT34902
