PLT-7537: Move channel CLI command posts system message to channel. (#8161)

* [PTL-7537] implement feature and test

* [PTL-7537] Update feature to post the the room requiring a username flag to be used

* [PTL-7537] update tests with username

* update test to remove changes to the test helper struct

* use the basic team and user

i18n/en.json

@@ -3130,6 +3130,14 @@
     "id": "app.channel.move_channel.members_do_not_match.error",
     "translation": "Cannot move a channel unless all its members are already members of the destination team."
   },
+  {
+    "id": "api.team.move_channel.success",
+    "translation": "This channel has been moved to this team from %v."
+  },
+  {
+    "id": "api.team.move_channel.post.error",
+    "translation": "Failed to post channel move message."
+  },
   {
     "id": "app.channel.post_update_channel_purpose_message.post.error",
     "translation": "Failed to post channel purpose message"