AWM: Date field with trailing whitespace in format causes save error on entry instead of during app creation

Steps to reproduce:

1. Click on "More application" from Application panel
2. Click on "Create your own"
3. Create Application
4. Insert a name and continue
5. Drag and drop "date" field
6. From "Configure" delete the hour and let only the "dd/MM/yyyy "(note the space after the yyyy)

*Expected result:*

If the format contains invalid characters (e.g., a trailing whitespace), the system should show an error banner at that moment. This allows the user to correct the format before the app is created, instead of encountering the error later when saving data.

*Actual result:*

The error occurs only during data entry when saving a record, blocking the user unexpectedly.