docker_secret, docker_config: allow to base64-decode data (#49688)

* Adjust docker_config and docker_secret to be more similar.

* Add data_is_b64 parameter to docker_secret and docker_config.

* Add changelog.

test/integration/targets/docker_config/tasks/test_docker_config.yml

@@ -70,6 +70,19 @@
       that:
          - not output.changed
 
+  - name: Create config again (base64)
+    docker_config:
+      name: db_password
+      data: b3BlbnNlc2FtZSE=
+      data_is_b64: true
+      state: present
+    register: output
+
+  - name: assert create config (base64) is idempotent
+    assert:
+      that:
+         - not output.changed
+
   - name: Update config
     docker_config:
       name: db_password

test/integration/targets/docker_secret/tasks/test_secrets.yml

@@ -70,6 +70,19 @@
       that:
          - not output.changed
 
+  - name: Create secret again (base64)
+    docker_secret:
+      name: db_password
+      data: b3BlbnNlc2FtZSE=
+      data_is_b64: true
+      state: present
+    register: output
+
+  - name: assert create secret (base64) is idempotent
+    assert:
+      that:
+         - not output.changed
+
   - name: Update secret
     docker_secret:
       name: db_password