Reworked and renamed script to generate Ansible collections

The script utils/build-galaxy-release.sh has been renamed to
utils/build-collection.sh, the script provides the same options, but
requires an extra argument now:

    build-collection.sh [options] rpm|aah|galaxy

The namespace and name are defined according to the argument:

    rpm     freeipa.ansible_freeipa   - General use and RPMs
    galaxy  freeipa.ansible_freeipa   - Ansible Galaxy
    aah     redhat.rhel_idm           - Ansible AutomationHub

The generated file README-COLLECTION.md is set in galaxy.yml as the
documentation entry point for the collections generated with aah and galaxy
as Ansible AutomationHub and also Ansible Galaxy are not able to render the
documentation README files in the collection properly.

The commit also changes the calls of utils/build-galaxy-release.sh to
utils/build-collection.sh.

infra/azure/templates/run_tests.yml

@@ -54,7 +54,7 @@ jobs:
 
   - script: |
       git fetch --unshallow
-      utils/build-galaxy-release.sh -i
+      utils/build-collection.sh -i rpm
     retryCountOnTaskFailure: 5
     displayName: Build Galaxy release
     condition: ${{ parameters.test_galaxy }}