API layer refactoring && avoid bypassing filtering options in User model

[kirrg001]

Please merge both commits separate.

First commit: Refactored the API layer: do not handle API response after pipelining

• this has a big underlying problem
• each task in the pipeline can modify the options
• e.g. add a proper permission context
• if we chain after the pipeline, we don't have access to the modified options object
• and then we pass the wrong options into the toJSON function of a model
• the toJSON function decides what to return based on options
• this is the easiest solution for now, but i am going to write a spec if we can solve this problem differently
• if we want to use the toJSON function to determine which model fields to return, we cannot do that without this change!

NOTE: I thought about a util for the response format, but i decided against at the moment, because i am not sure if we have to change a fundamental concept of how the API works (who returns what, who returns JSON, how do we guarantee that the options object is everywhere accessible, how are headers generated etc.). See for example this here - it only happens because the outer API level wants to add headers based on the state of a model.

Second commit: Removed bypassing option filtering in User model

• the tests were red on the first and i investigated why
• i had to create a PR with both commits, because the second commit is a result of the correctness of the first commit
• the logic in the User model bypasses filtering options!
• that is wrong, because if we filter out certain options e.g. include
• the tests from the previous commit fail because of this
• if we don't fix this logic, the tests won't pass, because as said, you can bypass certain logic e.g. remove roles from include
• this has worked before, because we passed the wrong options via the API layer
• was introduced here 014e2c8, because of Add count.posts support to user model on client #6122
• add proper tests to proof that these queries work!!

[kirrg001]

@ErisDS Ready for review.

[ErisDS]

🎉 This looks really good 👍