Missing key_type feature on 0.10

This issue is a (choose one):

• Problem/bug report.
• Feature request.
• Request for support. Note: Please try to avoid submitting issues for support requests. Use Gitter instead.

Checklist before submitting:

• I've searched for an existing issue.
• I've asked my question on Gitter and have not received a satisfactory answer.
• I've included a complete bug report template. This step helps us and allows us to see the bug without trying to reproduce the problem from your description. It helps you because you will frequently detect if it's a problem specific to your project.
• The feature I'm asking for is compliant with the JSON:API spec.

Description

On 0.10, key_type still exists from 0.9 but is not manage.

Indeed, ResourceIdentity only handles primary key. It might work if key_type is actually the primary key but it's not. Errors are raising.

For example, with id as a primary key and uuid as key_type.

This is a part of the job. I'm not 100% confident with all side effects that update might have. Maybe @lgebhardt can help with his knowledge.

Gitter on 11th of December 2020

Start by reading ResourceIdentity in version 0.10 and compare how key_type existed in 0.9. Reproduce the example with id as the primary key and uuid as key_type, then trace the errors and possible update side effects. Done means key_type is handled without those errors, with the intended behavior confirmed.