Update Brandings to new custom styles

[farmakiG]

Summary Upgrade customer brandings to the to the custom styles for a) the CSS custom variables for the runtime colors and b) bootstrap 5.0.

Details For a) all CSS custom properties defined in :root for light and dark theme must be updated and respective use of them in the Sass variables, such as $breadcrumb-bg, $dropdown-bg, etc. For b) test the upgrade to Bootstrap 5.0 and if there are any issues with the customer brandings.

Acceptance criteria

• [ ] Customer brandings are updated and redeployed in oscm-branding container
• [ ] Manual tests
• [ ] UI Screenshots

Additional context N/A.

[farmakiG]

Closed this task as explained, updated the customer brandings for the Runtime CSS vars.