For R.C. - Fleet UI: Unreleased bug fixes to command palette (unsupported screen size, hide fleet picker fleets based on page, add fleet picker empty state) (#47345)

[RachelElysia]

Issue

Closes #47295
Closes #47310
Closes #47311

Description

• Previously merged into main with Fleet UI: Unreleased bug fixes to command palette (unsupported screen size, hide fleet picker fleets based on page, add fleet picker empty state) #47345
• This is for the 4.87.0 R.C.

[codecov]

Codecov Report

❌ Patch coverage is 92.50000% with 3 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (rc-minor-fleet-v4.87.0@4e57679). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...ntend/components/CommandPalette/CommandPalette.tsx	70.00%	3 Missing ⚠️

Additional details and impacted files

@@                    Coverage Diff                    @@
##             rc-minor-fleet-v4.87.0   #47594   +/-   ##
=========================================================
  Coverage                          ?   67.20%           
=========================================================
  Files                             ?     2908           
  Lines                             ?   225861           
  Branches                          ?    11693           
=========================================================
  Hits                              ?   151783           
  Misses                            ?    60369           
  Partials                          ?    13709           

Flag	Coverage Δ
frontend	57.88% <92.50%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

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

🚀 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.