[pytx][large project] Migrate pytx CLI to use the same storage interfaces as HMA (if possible)

[Dcallies]

This is a multistep project, and it might be too difficult to do except for by the original goofballs who worked on the original libraries (mostly @Dcallies).

The first pass at storage interfaces lives in https://github.com/facebook/ThreatExchange/blob/main/python-threatexchange/threatexchange/cli/cli_config.py

We originally though we would be able to reuse the interface for HMA, but we quickly realized we could not, and so ended up with a separate implementation here: https://github.com/facebook/ThreatExchange/blob/main/hasher-matcher-actioner/src/OpenMediaMatch/storage/interface.py

Now looking back at the CLI, it would be nice to unify these two stacks.

Thus, we want to:

1. Migrate the HMA storage interfaces to the pytx library
2. Delete the HMA copy and use pytx as the source of truth
3. Duplicate the existing CLI implementation to follow the same interface
4. Replace all the calls in the existing cli code to use interfaced versions

• Migrate HMA Interfaces
  • ISignalTypeIndexStore
  • ISignalExchangeStore
  • IBankStore
• Delete the HMA copies
  • Also delete this accidental copy here: https://github.com/facebook/ThreatExchange/tree/main/python-threatexchange/threatexchange/cli/storage
• Plan out how to handle this mess on the CLI so we don't break previous versions
• Do whatever you planned on the CLI
  • Maybe [py-tx][mlh][tracking issue] Upgrade py-tx CLI storage implementation to dbm #1687 too
• ???
• Profit