[form] fix validation error handling
* type when possible ValidationError raised by the edit controller
* don't rely on repository to check required field
* turn css class used for field error message to errorMsg to avoid
confusion with the error class added to input
* fix css when errors are added by the form renderer
* fix form renderer to add the error message
[MESSAGES CONTROL]
disable-msg = C0301
[VARIABLES]
# Enable / disable this checker
enable-variables = yes
additional-builtins = _, display_name
[BASIC]
required-attributes=
attr-rgx = (w|[a-z_][a-z0-9_]{2,30})
variable-rgx = (w|[a-z_][a-z0-9_]{2,30})$
argument-rgx = (w|[a-z_][a-z0-9_]{2,30})$
[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception