ModelNodeFormBuilder is too strict when it comes to whitespaces

Some resources allow whitespaces in names:

/subsystem=batch-jberet/in-memory-job-repository=new\ in\ memory:add()

On the contrary it's impossible to create such resources using Web Console due to the 'No whitespace, no special chars allowed' restriction

Reason:
https://github.com/hal/core/blob/master/gui/src/main/java/org/jboss/as/console/mbui/widgets/ModelNodeFormBuilder.java#L470 / https://github.com/hal/core/blob/master/gui/src/main/java/org/jboss/as/console/mbui/widgets/ModelNodeFormBuilder.java#L476