feat(db): adding relational instance table

backend/v3/storage/database/dialect/postgres/migration/001_instance_table/up.sql

@@ -1,6 +1,13 @@
 CREATE TABLE IF NOT EXISTS zitadel.instances(
-    id VARCHAR(100) NOT NULL
-    , PRIMARY KEY (id)
-
-    , name VARCHAR(100) NOT NULL
-);
+  id TEXT NOT NULL PRIMARY KEY,
+  name TEXT NOT NULL,
+  default_org_id TEXT NOT NULL,
+  iam_project_id TEXT NOT NULL,
+  console_client_id TEXT NOT NULL,
+  console_app_id TEXT NOT NULL,
+  default_language TEXT REFERENCES languages(code),
+  created_at TIMESTAMPTZ DEFAULT NOW(),
+  updated_at TIMESTAMPTZ DEFAULT NOW(),
+  deleted_at TIMESTAMPTZ DEFAULT NULL
+);
+CREATE UNIQUE INDEX instance_name_index ON zitadel.instances (name);