Extend module_defaults by adding default groups for cloud modules (#44127)

Extends `module_defaults` by adding a prefix to defaults `group/` which denotes a builtin list of modules. Initial groups are: `group/aws`, `group/azure`, and `group/gcp`

test/integration/targets/module_defaults/tasks/main.yml

@@ -87,3 +87,28 @@
       - assert:
           that:
             foo.msg == "Hello world!"
+- name: Module group defaults block
+  module_defaults:
+    group/aws:
+      region: us-east-1
+      aws_secret_key: foobar
+  block:
+    - aws_s3_bucket_facts:
+      ignore_errors: true
+      register: s3
+    - assert:
+        that:
+          - "'Partial credentials' in s3.msg or 'boto3 required' in s3.msg"
+- name: Module group defaults block
+  module_defaults:
+    group/aws:
+      region: us-east-1
+      aws_secret_key: foobar
+      aws_access_key: foobar
+  block:
+    - aws_s3_bucket_facts:
+      ignore_errors: true
+      register: s3
+    - assert:
+        that:
+          - "'InvalidAccessKeyId' in s3.msg or 'boto3 required' in s3.msg"