Allow property name from deleted form to be used in entity list

[ktuite]

Closes getodk/central#695

When an entity list property was created through a draft form, it inserted a row of (datasetId, name, publishedAt) with null publishedAt. The query to insert a new property via the API (which would also immediately publish that property) flagged any new property insertion as a a conflict. The query has been updated to act as an upsert that will publish an unpublished property instead of failing.

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

[lognaturel]

One question to check my understanding but unless I got that wrong this looks ready to me!

[lognaturel]

If two drafts forms would create the same property the property is still only in the database once, right?

[ktuite]

Yes, the property is only listed once, but there's another table ds_property_fields that links those properties to the forms/form_defs/specific form fields that they came from (if they came from a form and not the API).

With two draft forms, it'll look like this in the database.

ds_properties [
  { id: 1, name: 'first_name', datasetId: 1, publishedAt: null },
  { id: 2, name: 'age', datasetId: 1, publishedAt: null }
]
ds_property_fields [
  { dsPropertyId: 1, formDefId: 3, path: '/name' },
  { dsPropertyId: 2, formDefId: 3, path: '/age' },
  { dsPropertyId: 1, formDefId: 4, path: '/name' },
  { dsPropertyId: 2, formDefId: 4, path: '/age' }
]

[lognaturel]

Great, makes sense. I was wondering whether there might be risk of the same property being published multiple times but it doesn’t seem so