A recent change to the openstack/releases ACLs pointed out that we don't
require function to be set on Gerrit label definitions. This would
result in the Gerrit default of MaxWithBlock which will interfere with
submit requirements.
Enforce that function is set and that the value is NoBlock via our
normalize script. This will add function = NoBlock entries to the file
if not set which results in a diff causing the test to fail.
In order to do this I refactored the submit-requirements and function
checking of the normalize script a bit. We now check the label section
independently of all other sections which allows us to reduce repetition
when dealing with label sections.
Change-Id: I9e83c1cde3fe20ea2c34cdf86cd2fd3006bfe62a
5fc22f27cf