Log when sub is force applied and apply create as update

[ktuite]

Closes getodk/central#702 and getodk/central#720

Should also help with getodk/central#699

What has been done to verify that this works as intended?

Why is this the best possible solution? Were any other approaches considered?

How does this change affect users? Describe intentional changes to behavior and behavior that could have accidentally been affected by code changes. In other words, what are the regression risks?

Does this change require updates to the API documentation? If so, please update docs/api.yaml as part of this PR.

Before submitting this PR, please make sure you have:

• run make test and confirmed all checks still pass OR confirm CircleCI build passes
• verified that any code from external sources are properly credited in comments or that everything is internally sourced

[ktuite]

Questions

• What to call extra details about how entity submission was processed and how to organize them? I started by just adding flags for forceProcessed, upsert, createAsUpdate, updateAsCreate to add to the entity def source details. updateAsCreate and forceProcessed were important for deciding whether to apply a create as an update.

• Where to add these extra details? In the entity def source feels right, but some of them could also be added to the audit log details. Would that be useful or redundant? Could be useful if showing audit log events about entities through the main system audit log. Whatever decisions made about this will be relevant to exposing the backlog.