Issue with generated migrations for multitenant resources

[revati]

Describe the bug
If i create resource with

  multitenancy do
    strategy :attribute
    attribute :organization_id
  end

and have another resource relating to this one, generated migration is wrong.
Fails with error:

** (Postgrex.Error) ERROR 42830 (invalid_foreign_key) there is no unique constraint matching given keys for referenced table "<table_name>"

To fix i need to add

  identities do
    identity :unique_id, [:id]
  end

which creates unique index with tenant (organization_id in this case prefix) so unique index [:organization_id, :id]
Then migrations works fine

Expected behavior
It would add corrcet unique indexes by default for primary fields with multitenancy

Runtime

• Elixir version - Elixir 1.14.3 (compiled with Erlang/OTP 25)
• Erlang version - Erlang/OTP 25
• OS - macos 13.1
• Ash version - 2.9.4

[zachdaniel]

Basically what we need to do here is, if the relationship points at the primary key of the target, we should not add the multitenancy attribute. This should be relatively easy to do.