fix: Add explicit refs to react-transition-group for React 19 support

[mattrunyon]

Tested with Settings menu slide out, sections collapse/expand. On a grid the copy handler tests the slide up and then the message fades out

Can also test the styleguide modal and toasts (the toasts must be dismissed by clicking the button, they don't auto-dismiss)

Also added a type override that should throw a type error if you remove nodeRef from any of the CSSTransition components. That way we don't accidentally introduce it in the future until we move off of react-transition-group.

[codecov]

Codecov Report

❌ Patch coverage is 12.76596% with 41 lines in your changes missing coverage. Please review.
✅ Project coverage is 43.89%. Comparing base (b369a51) to head (99d2373).

Files with missing lines	Patch %	Lines
packages/components/src/Collapse.tsx	0.00%	25 Missing ⚠️
...ages/components/src/transitions/FadeTransition.tsx	0.00%	11 Missing ⚠️
...ges/components/src/transitions/SlideTransition.tsx	0.00%	4 Missing ⚠️
packages/components/src/ToastNotification.tsx	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2534      +/-   ##
==========================================
- Coverage   43.91%   43.89%   -0.02%     
==========================================
  Files         763      763              
  Lines       42874    42906      +32     
  Branches    11005    11011       +6     
==========================================
+ Hits        18827    18833       +6     
+ Misses      24032    24027       -5     
- Partials       15       46      +31     

Flag	Coverage Δ
unit	43.89% <12.76%> (-0.02%)	⬇️

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[bmingles]

Changes look good overall. Tested the functionality as well. Left comments for some style objects and comment example.

[mattrunyon]

There's another fix for React 19 (replacing react-beautiful-dnd with @hello-pangea/dnd) which I have added locally over this + the React 18 PR. But it failed a bunch of e2e tests so I'll have to do more testing. Might spin that into a separate PR, but both are needed for DH-20098

[mattrunyon]

I'll handle the other React 19 changes in a separate PR

[bmingles]

LGTM