feat: add scrim to common remove modal

[bryce-mcmath]

Summary of Changes

Users were getting confused by the background of the common remove modal, thinking they could still press buttons in the header. Adding a scrim to dim the content behind the modal communicates to the users that those elements aren't accessible. Here is the before and after:
No scrim

With scrim

Related Issues

N/A

Pull Request Checklist

Tick all boxes below to demonstrate that you have completed the respective task. If the item does not apply to your this PR check it anyway to make it apparent that there's nothing to do.

• All commits contain a DCO Signed-off-by line (we use the DCO GitHub app to enforce this);
• Updated LICENSE-3RD-PARTY.md for any added dependencies or vendored components;
• Updated documentation as needed for changed code and new or modified features;
• Added sufficient tests so that overall code coverage is not reduced.

If you have any questions to any of the points above, just submit and ask! This checklist is here to help you, not to deter you from contributing!

Pro Tip 🤓

• Read our contribution guide at least once; it will save you a few review cycles!
• Your PR will likely not be reviewed until all the above boxes are checked and all automated tests have passed.

PR template adapted from the Python attrs project.

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (9d9dc8f) 61.48% compared to head (24c7f62) 61.48%.

Files	Patch %	Lines
...y/core/App/components/modals/CommonRemoveModal.tsx	50.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1050   +/-   ##
=======================================
  Coverage   61.48%   61.48%           
=======================================
  Files         170      170           
  Lines        5450     5450           
  Branches     1570     1570           
=======================================
  Hits         3351     3351           
  Misses       2075     2075           
  Partials       24       24           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.