Table refactor.

- Generalizes table construction/deconstruction.
- Merges racks into tables as a subtype (table/rack).
- Fixes #7509.

- [X] Test table construction.
- [X] Test table deconstruction.
- [X] Test table upgrading.
- [X] Test table de-upgrading.
- [X] Test rack construction.
- [X] Test rack deconstruction.
- [X] Test flipping racks.
- [ ] Test holoracks.
- [X] Test building racks alongside tables.
- [ ] Retest welder weakening.
- [ ] Test the map.