Removed Exception being thrown when valueOptions property is empty
Removed unrequired test for DomainException being thrown
#6649 #6655 - rendering a multicheckbox without value options should produce an empty string
#6649 #6655 - adding `@group` annotations for newly introduced tests
Merge branch 'hotfix/#6655-#6649-allow-empty-form-element-value-options-in-form-element-renderer'

Close #6655
Close #6649