Make ingestion model optional in update_db_model function

[isaacna]

Description

• In upload_db_model, we allow ingestion_model to be an optional param. However, if the db model already exists and an ingestion model isn't passed, then a uniqueness error is thrown.
• There are some places in the event gather pipeline where we call upload_db_model_task without a corresponding ingestion model because we don't really need an ingestion model. Th
• This is an unlikely edge case, but there could be a situation where an audio file is deleted from the file store, but the corresponding file db models are not. This could be happen if we're doing something like data cleanup or a backfill which causes inconsistencies.
• There are a few different ways to refactor this
  • We could fix this by changing the upload_db_model logic and removing the ingestion model is not None check, and changing update_db_model to take in Union[Model, IngestionModel] instead. It may also make more sense to have separate params for a db model vs ingestion model in update_db_model since the logic may differ a bit
  • We could also change upload_db_model to only accept a db_model instead of ingestion_model, and update_db_model to take in existing_db_model and proposed_db_model. This would probably make the both functions more simple, however would require us to create extra db models outside of those functions

Expected Behavior

• Uniqueness error to not get triggered when upload_db_model_task is called with None for ingestion_model when an existing db model is present

[isaacna]

Closing as this is no longer necessary as the update code will be removed in #74.

Using deterministic keys lets us just upsert so the update_db_model function will be removed.

[isaacna]

Closing