* Added validation for errors when the Import Field to map isn't setted
* A slightly correction to the error message
* Added the translation strings for the Error Message
* More helpful text on how the custom validator works
* Clarified language of custom format, fixed regex example
* Fixed regex example in placeholder
* Added comments to custom fields
* Added regex validation string
* Added valid_regex validator in format requirements
* Removed useles comments
* Fixes#4236 - validate the regex custom validation
This is a little janky, as it breaks up the errors into multiple screens if you don't have a status label type AND don't have a name. This is because the model-level validation won't work since we transmogrify that dropdown list of status label types into boolean values for the DB. Should eventually find a less clunky way to handle this, but needed to get a fix in now.