Insert temp tables before other migrations take place.

[ChrisPenner]

Old Context:

• Arya is looking into how to 'freeze code' which is used in migrations because a recent change to saveObject; Currently looking into copy-pasting all existing code and 'Weeder'ing out any code not used by the migration
  • Chris suggests that maybe we should look into simpler options to save time while we're in crunch mode.
  • Option 1: Use an old version of UCM to do some of the updates
    • Arya: kind of janky
  • Option 1b: separate migration tool
  • Option 2: Copy monorepo to migration-specific package + weed out unnecessary dependencies -A
    • getting weeder working might be a big job / low priority?
  • Option 3: Copy monorepo to migration-specific package + don't weed out unnecessary dependencies
    • high compilation times
      • no, this should be okay if pulled out of the monorepo
    • high binary sizes
  • Option 4: Copy monorepo to migration-specific package + weed out some unnecessary dependencies -M/T
    • Just try the insert and check for a 'missing table exception' or w/e
  • Option 5: Check for Temp Table existence (or schema version) in saveObject
    • global variables -A -C (temporarily, just until we have more time for a better solution)
  • Option 6: Check/save schema version in runTransaction or something
  • Note: We want a principled way to handle this in future migrations, regardless.
  • Note: Majority of codebases don't need to be migrated
  • Note: Migrations don't need to be run in the same transaction
  • Note: In some cases, pushing a codebase to Share w/ old ucm and pulling it back with a new one might be faster / more convenient.

New:

This PR take an alternative approach, the only requirement for old migrations to work is that these tables EXIST, they don't need to be populated with anything at all, so we can just add those tables as a 'pre-migration' step whenever we run a migration.

It's still a hack that should be removed later, but it's safer, simpler, adds less junk code, and is more performant than our other approaches.

• Tested on commit 5cf1da4 from base which is a v1 codebase.

[mitchellwrosen]

Note: let's change the create table if not existss back to create tables once we implement the freezy fix.