[FIX] Fixed app icon aligntment for extensions with image icon

[eva-vashkevich]

Summary

Fixes #12758

Changed css to exclude pins instead of specifying which element to apply to include more cases.

Occurred changes and/or fixed issues

Technical notes summary

Areas or cases that should be tested

1. Install an extension from https://nwmac.github.io/rancher-dev-portal/
2. All items on app bar (top level menu) should be positioned the same
3. Create a new imported cluster without actually importing it.
4. Pin the new cluster and local cluster. Pin positioning should be the same.

Areas which could experience regressions

Top level menu application bar

Screenshot/Video

Checklist

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• 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

[momesgin]

LGTM