BREAKING: Consolidate configuration for migrations in values.yaml

[marlenekoh]

Consolidate configuration for migrations in values.yaml

Description

Currently the migrations job is being configured in 2 places: .datastore.migrations and .migrate. I have removed .migrate and shifted all keys to .datastore.migrations.

Also sneaked in a possible fix for #2 for .grpc.tls.enabled

References

#2

Review Checklist

• [x] I have clicked on "allow edits by maintainers".
• [ ] I have added documentation for new/changed functionality in this PR or in a PR to openfga.dev [Provide a link to any relevant PRs in the references section above]
• [ ] The correct base branch is being used, if not main
• [ ] I have added tests to validate that the change in functionality is working as expected