Support skipping fields in Queryable derive (falls back to Default impl)

[Ten0]

Not sure if there was a feature request for this, but I happened to need it and felt it wouldn't be too hard to implement.

Does this seem reasonable? (We perhaps just want this also be available on the other derives?)

[weiznich]

See #1582 and #860 for prior discussion.
That written: I'm worried about such a feature as it opens to door for users to easily construct N + 1 query constructs instead of using the associations API.
This means I would like to see a good motivation why this is necessary and why this cannot be solve differently.

[Ten0]

Oh I did not expect there to be so much discussion on that topic already!
Funny how we had started the same exact implementation, though I iterated a bit more.

Overall not super convinced by the arguments against there, but turning this into a draft as there seems to not be a consensus towards implementation.

[AJTJ]

Would love if this were to be picked up again :)

[Ten0]

The problem here is not workforce but the decision on the relevant discussion. If you have new insights on the topic feel free to add them there. 🙂