feat: simplification of default-value specification in FieldMetadata (#4592)

* feat: wip refactor default-value

* feat: health check to migrate default value

* fix: tests

* fix: refactor defaultValue to make it more clean

* fix: unit tests

* fix: front-end default value

packages/twenty-server/src/engine/metadata-modules/field-metadata/utils/generate-default-value.ts

@@ -9,23 +9,21 @@ export function generateDefaultValue(
     case FieldMetadataType.TEXT:
     case FieldMetadataType.PHONE:
     case FieldMetadataType.EMAIL:
-      return {
-        value: '',
-      };
+      return "''";
     case FieldMetadataType.FULL_NAME:
       return {
-        firstName: '',
-        lastName: '',
+        firstName: "''",
+        lastName: "''",
       };
     case FieldMetadataType.LINK:
       return {
-        url: '',
-        label: '',
+        url: "''",
+        label: "''",
       };
     case FieldMetadataType.CURRENCY:
       return {
         amountMicros: null,
-        currencyCode: '',
+        currencyCode: "''",
       };
     default:
       return null;