fix(Dashboard): Sidepanel positioning

[geido]

SUMMARY

This PR fixes several positioning issues with the sidepanel in Dashboard.

Fixes #17158

BEFORE

See #17158

AFTER

Video.Game.Sales.mp4

TESTING INSTRUCTIONS

1. Open a Dashboard
2. Scroll at the bottom
3. Edit the Dashboard
4. Make sure the sidepanel is showing properly

ADDITIONAL INFORMATION

• Has associated issue: [dashboard edit mode] The "add components" menu is not displayed if the page was scrolled down before clicking the edit button #17158
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[codecov]

Codecov Report

Merging #17200 (8eac7af) into master (860e481) will increase coverage by 0.12%.
The diff coverage is 88.88%.

@@            Coverage Diff             @@
##           master   #17200      +/-   ##
==========================================
+ Coverage   76.94%   77.06%   +0.12%     
==========================================
  Files        1039     1037       -2     
  Lines       55580    55671      +91     
  Branches     7575     7607      +32     
==========================================
+ Hits        42764    42904     +140     
+ Misses      12566    12517      -49     
  Partials      250      250              

Flag	Coverage Δ
javascript	71.26% <88.88%> (+0.28%)	⬆️

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

Impacted Files	Coverage Δ
...d/components/DashboardBuilder/DashboardBuilder.tsx	90.51% <81.81%> (+0.33%)	⬆️
.../src/dashboard/components/BuilderComponentPane.tsx	96.87% <93.33%> (-3.13%)	⬇️
superset-frontend/src/dashboard/util/constants.ts	100.00% <100.00%> (ø)
...erset-frontend/src/components/Pagination/index.tsx	72.72% <0.00%> (-27.28%)	⬇️
...Filters/FilterBar/FilterControls/FilterControl.tsx	94.87% <0.00%> (-5.13%)	⬇️
...mponents/controls/MetricControl/MetricsControl.jsx	38.18% <0.00%> (-3.88%)	⬇️
...tend/src/filters/components/Select/controlPanel.ts	58.33% <0.00%> (-3.21%)	⬇️
...eFilters/FiltersConfigModal/FiltersConfigModal.tsx	87.13% <0.00%> (-0.59%)	⬇️
...frontend/src/dashboard/components/Header/index.jsx	68.30% <0.00%> (-0.41%)	⬇️
...et-frontend/src/components/TableSelector/index.tsx	74.28% <0.00%> (-0.25%)	⬇️
... and 49 more

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[villebro]

Minor bycatch related to a variable used here. LGTM and works great in testing, but would really prefer to get @michael-s-molina or @kgabryje to sign off on the styling part.

[pkdotson]

/testenv up

[github-actions]

@pkdotson Ephemeral environment spinning up at http://54.185.33.35:8080. Credentials are admin/admin. Please allow several minutes for bootstrapping and startup.

[kgabryje]

Lgtm!

[github-actions]

Ephemeral environment shutdown and build artifacts deleted.