Testing on Datasource changes

[ljstella]

When we calculate changes between two branches in order to run tests, we currently do not catch data source object changes as content dependencies. Following the same path in which we calculate macros and lookups as being content dependencies, this PR will attempt to change the diff calculation to include data source object changes.

Notably, this will then trigger the testing for each of these detections when we have an "Auto Update TA" PR like so: splunk/security_content#3154. (See Note at end)

This testing will provide the confidence and verification that such changes can be merged without issues.

Note:
Those PRs currently don't update contentctl.yml, which appears to still be used for testing, so until we decide how to reconcile those here, or update the code powering those PRs to also make those changes, this will trigger tests but still using the old TAs. We also don't really have any testing afaict to confirm that the TA version change does not alter sourcetypes or fields- those will hopefully become apparent via the actual testing, but that's not necessarily guaranteed depending on the original GDI mechanism

[ljstella]

Update: splunk/security_content#3197 should handle updates to contentctl.yml which gives us a path forward here.

[pyth0n1c]

Tested these changes locally with a number of changes to detections and data_sources. It looks like it picks up those changes correctly, this looks good to me!

[pyth0n1c]

Approved again. I asked the owner to update the version in prep for a contentctl release and it has been done.