feat(databases): backup configurations resource

[fbarrento]

Parent

#32

What to build

server($id)->databaseBackups() (backup configurations) list/get/create/update/delete (/database/backups).

Acceptance criteria

• BackupConfiguration DTO + create/update data + list-options; BackupProvider enum (s3/spaces/hetzner/ovh/scaleway/custom)
• Requests: GET/POST /database/backups, GET/PUT/DELETE /database/backups/{backupConfiguration}
• Resource wired on ServerResource; backup-provider credentials/secrets redacted in fixtures
• Live-recorded fixtures (against the db-type server from feat(databases): database schemas resource #34); 100% coverage

Blocked by

• Blocked by feat(databases): database schemas resource #34