feat: Add folderId column to the flow model

packages/backend/src/models/__snapshots__/flow.test.js.snap

@@ -12,6 +12,13 @@ exports[`Flow model > jsonSchema should have correct validations 1`] = `
     "deletedAt": {
       "type": "string",
     },
+    "folderId": {
+      "format": "uuid",
+      "type": [
+        "string",
+        "null",
+      ],
+    },
     "id": {
       "format": "uuid",
       "type": "string",

packages/backend/src/models/flow.js

@@ -28,6 +28,7 @@ class Flow extends Base {
       id: { type: 'string', format: 'uuid' },
       name: { type: 'string', minLength: 1 },
       userId: { type: 'string', format: 'uuid' },
+      folderId: { type: ['string', 'null'], format: 'uuid' },
       remoteWebhookId: { type: 'string' },
       active: { type: 'boolean' },
       publishedAt: { type: 'string' },