Add params to set_id block

[henvo]

Hey thanks for creating this repo and keeping fast_jsonapi alive

---

A previous pull request added a block to the ObjectSerializer.set_id class
method, which allows passing a block to the set_id method. Currently
this block takes only one argument record:

set_id do |record|
  "#{record.name.downcase}-#{record.id}"
end

This PR adds another argument params to the block:

set id do |record, params|
  params[:admin] ?  record.id : "#{record.name.downcase}-#{record.id}"
end

This customization can be useful in situation where we serve different
clients that may need different IDs. One nice side effect is also that
the set_id method has the same method signature as the attribute
method.

This PR was copied from Netflix/fast_jsonapi#380

[stas]

@henvo thank you for the PR. This seems like a breaking change. @jopotts @kpheasey what do you think, should we consider the merge for this release?

[kpheasey]

@stas This looks good to me. Can you explain why this is a breaking change.

The optional second params argument continues a convention and extends functionality w/o sacrificing performance. I actually had a similar use case a month ago and it would have been helpful. We got around it by setting a current user on the model and then referencing it from there, which is not ideal.

[stas]

@henvo @kpheasey apologies, I missed the part where the params is optional.

[kpheasey]

@henvo I updated the PR to merge into the dev branch. Can you resolve the conflicts?

[henvo]

Hey all thanks for the feedback. I fixed the merge conflicts.