Allow deleting/writing the same tuple key in the same Write call

[aaguiarz]

Checklist

• I agree to the terms within the OpenFGA Code of Conduct.

Describe the problem you'd like to have solved

If we want to change the context values of a tuple, I need to delete/write the tuple in the same write() call.

However, OpenFGA tries to write it first, and it returns an error as it's duplicated.

Describe the ideal solution

We should first process deletes and then writes.

Alternatives and current workarounds

Make 2 write calls in different transactions.

Additional context

No response