## Problem description
During tests we found concurrency issues in the relational table
projections. Tests got flaky if a table (e.g. organization domains) had
too many foreign keys to tables which were projected by another handler.
## Resolution
The projections of the relational tables got merged into one handler to
enforce sequential reduction of events.
## Additional info
- closes https://github.com/zitadel/zitadel/issues/11703
- closes https://github.com/zitadel/zitadel/issues/10810
---------
Co-authored-by: Marco Ardizzone <[email protected]>
This pull request introduces a new feature that allows adding, updating,
and querying metadata for organizations. The changes are primarily in
the backend and include new database tables, repositories, and domain
logic to support organization metadata.
## Changes
* New `org_metadata` table: A new table `zitadel.org_metadata` is
introduced to store metadata for organizations. It includes columns for
`instance_id`, `org_id`, `key`, and `value`. The `value` is stored as a
`BYTEA` type to allow for flexible data storage.
* New `OrganizationMetadataRepository`: A new repository
`OrganizationMetadataRepository` is created to handle all database
operations for organization metadata. It provides methods to `Get`,
`List`, `Set`, and `Remove` metadata.
* New `org_metadata_relational_projection`: A new projection
`org_metadata_relational_projection` is added to update the
`zitadel.org_metadata` table based on events. It handles `MetadataSet`,
`MetadataRemoved`, and `MetadataRemovedAll` events.
* Updated `OrganizationRepository`: The `OrganizationRepository` is
updated to support loading organization metadata. A new method
`LoadMetadata` is added to enable joining the `org_metadata` table when
querying for organizations.
* Updated Organization domain: The Organization domain model is updated
to include a new field `Metadata` of type `[]*OrganizationMetadata`.
## Additional Info
* Extensible Design: The new metadata feature is designed to be
extensible, allowing for future enhancements such as indexing on
specific JSON fields within the `value` column.
* closes https://github.com/zitadel/zitadel/issues/10206
* closes https://github.com/zitadel/zitadel/issues/10214
