[14.0][ADD] Theme Kaizen

[reneeduijzers]

Theme Kaizen is a theme on it's own and includes the design principles of https://ubports.com.

Adjusted the theme to be fully compatible with the new flexible odoo14 web editor, keeping all customization options intact.

The development of this module has been financially supported by UBports.

[thomaspaulb]

@reneeduijzers The same theme in 13.0 has undergone quite some review before being accepted and merged.

For this 14.0 version, you should now thus propose it in a different way, as explained by this guide (see howto - technical near the bottom).

This has the benefit that:

• We dont lose fixes that were done in 13.0
• The pull request will retain original commits from original authors and thus any code in any version of the theme is tracable to the commit + author where it is from
• The pull request will clearly highlight the differences between 13.0 and 14.0 so reviewers can focus on that part only and make it be merged faster

So, please do it in that way! If you need any help, don't hesitate to ask, and perhaps @tarteo can help, as well.