[BUG] Officer Creation does not require a data source

[DMalone87]

Describe the bug
It should not be possible to create a Data node in the index without attaching a source. However, the current implementation of the Officer POST endpoint allows just that.

To Reproduce
Steps to reproduce the behavior:
POST - Officer without a valid source UID.

Expected behavior
The API should pass a 422 response

Additional context
When a valid source UID IS included, make sure to attach the officer to that source.
Alternatively, the correct source could be inferred from the logged in user.