add module aws_codecommit to represent AWS CodeCommit (#46161)

* kick off

* done for the day

* beta code and test

* fix a typo

* boto3_conn and boto_exception aren't used in this code, ec2_argument_spec is used but unneeded.

* Returning when find a match avoids doing extra work, especially when pagination is involved

* add new permissions for test

* (output is changed) is preferred over accessing the attribute directly.

* pass the result through camel_dict_to_snake_dict() before returning it.

* AnsibleAWSModule automatically merges the argument_spec.

* deletes the created resources even if a test fails.

* AnsibleAWSModule automatically merges the argument_spec.

* fix typo

* fix pep8

* paginate list_repositories

* specify permissions for test

* cut the unnecessary code.

* add return doc string

* add missed ':'

* fix syntax error: mapping values are not allowed here

* add description for return

* fix syntax error

* rename module name and turn off automated integration test.

hacking/aws_config/testing_policies/devops-policy.json

@@ -0,0 +1,17 @@
+{
+    "Version": "2012-10-17",
+    "Statement": [
+      {
+        "Sid": "AllowCodeCommitModuleTests",
+        "Effect": "Allow",
+        "Action": [
+          "codecommit:ListRepositories",
+          "codecommit:CreateRepositories",
+          "codecommit:DeleteRpositories"
+        ],
+        "Resource": [
+          "arn:aws:codecommit:*"
+        ]
+      }
+    ]
+}