Expand valid resource name character set

This allows all printable unicode characters and horizontal whitespace
characters in resource names (flavors, aggregates, cells, etc.), as
opposed to the rather limited set that was previously available. This
follows the principle of not creating unnecessary restrictions.

Implements: blueprint relax-resource-name-restrictions
Closes-Bug: 1366778
Change-Id: I35104852797dcba4594af4361bf9226e16bfb114
Merge "Expand valid resource name character set"