Add test to check error message for category-create with long category name
Add test to check error message for category-create with long category name

Test case checks that error message after calling category-create with
long category name (longer than 80 characters)contains user friendly substring

Targets: blueprint murano-cli-integration-test-coverage

Change-Id: Id6c211b058b3b39320e613968bd04447389f2744

openstack/python-muranoclient,openstack/python-muranoclient