i18n: the message of a validation error is not translated

Description of problem:
The only text which is not translated in the editor which shows validation errors is a message of an error.

Version-Release number of selected component (if applicable):
6.0.2 ER2 BPMS

Steps to Reproduce:
1. use localization for de, ja, es, ru

• start $LC_ALL=es_ES.UTF-8 ./standalone.sh or
• go to http://localhost:8080/business-central/org.kie.workbench.KIEWebapp/KIEWebapp.html?locale=es_ES
  2. create a process without name
  3. validate the process

Actual results:
The message of the error is "Process has no name".

Expected results:
The message of the error is "Process has no name" translated to the selected language (for example spanish).

Additional info: