Merge and modify PR from @Kurnihil

Merging a PR from @Kurnihil into the already rebased branch.
Made some small changes to make it work with newer changes.

Some finetuning is probably still needed.

Co-authored-by: Daniele Andrei <daniele.andrei@geo-satis.com>
Co-authored-by: Kurnihil

migrations/mysql/2023-06-02-200424_create_organization_api_key/up.sql

@@ -6,3 +6,5 @@ CREATE TABLE organization_api_key (
 	revision_date	DATETIME NOT NULL,
 	PRIMARY KEY(uuid, org_uuid)
 );
+
+ALTER TABLE users ADD COLUMN external_id TEXT;