(maint) Update GRM configuration

We are consolidating labels that are in use across our repositories, so this commit brings the GRM configuration up to date.  Namely, we are using Enhancement now, where we might have used Improvement or Feature before.  Also, removed C4B Feature as this has never been used. Finally, update the Internal Refactoring label to use the new `Area - Refactor` label.

Signed-off-by: Gary Ewan Park <gep13@gep13.co.uk>

Author: gep13

GitReleaseManager.yaml

@@ -1,14 +1,11 @@
 issue-labels-include:
   - Breaking Change
   - Deprecate
-  - Feature
-  - C4B Feature
+  - Enhancement
   - Bug
-  - Improvement
   - Documentation
   - Dependency Change
 issue-labels-exclude:
-  - Internal Refactoring
   - Build Automation
   - NO RELEASE NOTES
 issue-labels-alias: