Update colors for SUSE Prime Theme

[rak-phillip]

Summary

This updates the Prime theme to use the new styles defined by the UX team.

Fixes #15168

Occurred changes and/or fixed issues

• Updates colors in the modern theme to match the new designs
• Updates Prime logos

Technical notes summary

This modifies colors and variables present in shell/assets/styles/themes/_suse.scss. The aim of this PR is to focus on colors for the Prime theme.

Areas or cases that should be tested

Set the brand to "suse".

Areas which could experience regressions

Accessibility concerns with regards to color contrast. Mismatched colors in components.

Screenshot/Video

NA

Checklist

• The PR is linked to an issue and the linked issue has a Milestone, or no issue is needed
• The PR has a Milestone
• The PR template has been filled out
• The PR has been self reviewed
• The PR has a reviewer assigned
• The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
• The PR has reviewed with UX and tested in light and dark mode, or there are no UX changes
• The PR has been reviewed in terms of Accessibility

[richard-cox]

styles/code look good, light mode looks nice, question about dark mode (in slack)

Bonus, not related to PR..... We should (in another PR) update the spinner colour in the splash page to align with the modern theme (https://github.com/rancher/dashboard/blob/master/shell/public/index.html#L32). Unfortunately we can't determine brand (suse / modern) at that point in loading, only theme (light / dark)

[richard-cox]

Lets get everything in a see how that dark mode green works with all the other changes

[nwmac]

@rak-phillip There was 1 genuine e2e test failure - we were checking the width of the SUSE logo, and this had changed. I have pushed a commit to update the e2e test.

[nwmac]

@rak-phillip Hope you don't mind - got this to pass gates now, will merge.