Remove legacy SpaceInfo

[Wumpf]

What

• Fixes Re-engineer the space-view heuristics engine #4388
  • this is the last piece 🥳
• Related to
  • DisconnectedSpace now only applies to spatial space views #4935
  • Add/remove entities modal doesnt allow adding to a 2D space view #4826

SpaceInfo used to be used to determine space connectivity, this is by now done by SpatialTopology

Not a "pure" refactor: Slight changes in behavior

• Adding a space view via the 'plus' top left uses the default-created list, not the now removed "all" list (which was poorly defined)
• Similarly, suggestions for root now use the default-created list
• adding entities via the add-ui no longer uses any kind of transform analysis (it relied on SpaceInfo)
  • Does not fix Add/remove entities modal doesnt allow adding to a 2D space view #4826
  • .. since it still won't allow adding things that aren't visualizable at all

Checklist

• I have read and agree to Contributor Guide and the Code of Conduct
• I've included a screenshot or gif (if applicable)
• I have tested the web demo (if applicable):
  • Using newly built examples: app.rerun.io
  • Using examples from latest main build: app.rerun.io
  • Using full set of examples from nightly build: app.rerun.io
• The PR title and labels are set such as to maximize their usefulness for the next release's CHANGELOG

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[jleibs]

Finally! 🎉