Fixed cluster list in burger menu having unnecessary horizontal scroll

[eva-vashkevich]

Summary

Fixes #11809

Changed width setting so that it doesn't need scroller on smaller screens.
Tested on Chrome, Firefox and Safari

Occurred changes and/or fixed issues

N/A

Technical notes summary

N/A

Areas or cases that should be tested

Burger menu:

• Check cluster list with burger menu with 1 cluster both open and collapsed. Try different window sizes.
• Add more clusters (ie import custom clusters) until it requires virtual scroll in the side menu. Repeat step 1.
  No horizontal scroll should be visible, clusters should be able to get pinned, layout should seem reasonable.

Areas which could experience regressions

N/A

Screenshot/Video

https://github.com/user-attachments/assets/e69cff4c-0597-4750-96dc-2e5884c8fd77
https://github.com/user-attachments/assets/fc64477b-a471-408a-bcc2-1efcc2a42356

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

[eva-vashkevich]

Updated css.

[momesgin]

Updated css.

Interestingly I can't see the pins touch the edge of TopLevelMenu on my machine unlike your last screenshot, I tried changing the OS's scroll bar setting but still it doesn't happen. Personally I don't like the pins touching the edge, but at the end of the day that's up to the designers.

Besides that I found two issues after this change, tooltip position and pin icons distance from the edge

before:

after:

[momesgin]

LGTM