Time Strip fixes for overflow and Inspector layout

[charlesh88]

Closes #8169

Describe your changes:

• CSS and markup changes to fix swimlane overflow and Inspector layout for Time Strip.

All Submissions:

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Is this a notable change that will require a special callout in the release notes? For example, will this break compatibility with existing APIs or projects that consume these plugins?

Author Checklist

• Changes address original issue?
• Tests included and/or updated with changes?
• Has this been smoke tested?
• Have you associated this PR with a type: label? Note: this is not necessarily the same as the original issue.
• Have you associated a milestone with this PR? Note: leave blank if unsure.
• Testing instructions included in associated issue OR is this a dependency/testcase change?

Reviewer Checklist

• Changes appear to address issue?
• Reviewer has tested changes by following the provided instructions?
• Changes appear not to be breaking changes?
• Appropriate automated tests included?
• Code style and in-line documentation are appropriate?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 56.74%. Comparing base (569c7ff) to head (8874434).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8170      +/-   ##
==========================================
- Coverage   57.34%   56.74%   -0.61%     
==========================================
  Files         700      700              
  Lines       28142    28142              
  Branches     2744     2744              
==========================================
- Hits        16139    15968     -171     
- Misses      11667    11834     +167     
- Partials      336      340       +4     

Flag	Coverage Δ
e2e-ci	63.07% <ø> (+0.02%)	⬆️
e2e-full	23.59% <ø> (-18.77%)	⬇️
unit	48.35% <ø> (-0.18%)	⬇️

Files with missing lines	Coverage Δ
src/plugins/timeline/TimelineElementsContent.vue	0.00% <ø> (ø)
src/plugins/timeline/TimelineElementsPool.vue	0.00% <ø> (ø)

... and 14 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 569c7ff...8874434. Read the comment docs.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.