IBX-8054: Add extension point for doing cleanup during delete operation

[vidarl]

🎫 Issue	IBX-8054

Related PRs:

• https://github.com/ibexa/connector-dam/pull/59

Description:

Make an extension point for doing cleanup during delete operation.
For instance, field types may need to clean up data in ezcontentobject_attribute table for related content

For QA:

Documentation:

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[adamwojs]

@vidarl How this will affect performance ?

[vidarl]

@vidarl How this will affect performance ?

The use of !tagged_iterator is dealt with at compile time, so shouldn't impact performance much.

But it is needed to loop over the handlers, indeed. Calling a method for each handler will cause a small overhead, but overall performance will mostly depend on what each handler actually needs to do.
But in regards to performance, I see no fundamental different between this approach and our trash events. A benefit here is that you can potentially do things faster as you are on in the persistence layer, not on Content layer.

That said, I am fine with removing the postDeleteContent(). I have no eminent use for it. I just added it as we have before and after events