Small UI tweaks for add track workflow

[cmdcolin]

• Use @jbrowse/core/ui/AssemblySelector for the add track workflow instead of custom assembly selector component
• Make it so the AssemblySelector isn't so eager to reach for localStorage to enable the above
• Refactor the categories code for track adapter selector in add track workflow
• Make it so adapterMetadata has optional slots instead of |null
• Fix bug running action in the render instead of in useEffect in ConfirmTrack xref Bug: too hard to fix "Cannot update a component from inside the function body of a different component." facebook/react#18178 (comment)
• Make the add-track workflow selection read "Default add track workflow" instead of just Default, which stands out a little more visually
• Use variant=contained select boxes in add track workflow, I think it makes them more clearly a select drop box

[codecov]

Codecov Report

Merging #3387 (ce2f160) into main (0dfd9bf) will increase coverage by 0.02%.
The diff coverage is 63.26%.

@@            Coverage Diff             @@
##             main    #3387      +/-   ##
==========================================
+ Coverage   59.32%   59.35%   +0.02%     
==========================================
  Files         812      819       +7     
  Lines       29761    29757       -4     
  Branches     7160     7154       -6     
==========================================
+ Hits        17656    17661       +5     
+ Misses      11917    11908       -9     
  Partials      188      188              

Impacted Files	Coverage Δ
packages/core/pluggableElementTypes/AdapterType.ts	83.33% <ø> (ø)
plugins/alignments/src/HtsgetBamAdapter/index.ts	75.00% <ø> (ø)
plugins/alignments/src/SNPCoverageAdapter/index.ts	100.00% <ø> (ø)
...ins/comparative-adapters/src/ChainAdapter/index.ts	75.00% <ø> (ø)
...ins/comparative-adapters/src/DeltaAdapter/index.ts	75.00% <ø> (ø)
...arative-adapters/src/MCScanAnchorsAdapter/index.ts	75.00% <ø> (ø)
...e-adapters/src/MCScanSimpleAnchorsAdapter/index.ts	75.00% <ø> (ø)
...s/comparative-adapters/src/MashMapAdapter/index.ts	75.00% <ø> (ø)
...ugins/comparative-adapters/src/PAFAdapter/index.ts	100.00% <ø> (ø)
...ugins/config/src/FromConfigAdapter/configSchema.ts	50.00% <ø> (ø)
... and 27 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[cmdcolin]

also suggests moving adapterMetadata.displayName to just displayName