Implement room_alias_name option for client room creation

lib/architex_web/client/controllers/room_controller.ex

@@ -25,6 +25,9 @@ defmodule ArchitexWeb.Client.RoomController do
         {:error, :authorization} ->
           put_error(conn, :invalid_room_state)
 
+        {:error, :alias} ->
+          put_error(conn, :room_in_use, "The requested alias is already in use.")
+
         {:error, :unknown} ->
           put_error(conn, :unknown)
       end

lib/architex_web/error.ex

@@ -14,6 +14,7 @@ defmodule ArchitexWeb.Error do
     unauthorized: {400, "M_UNAUTHORIZED", "The request was unauthorized."},
     invalid_param: {400, "M_INVALID_PARAM", "A request parameter was invalid."},
     missing_param: {400, "M_MISSING_PARAM", "A request parameter is missing."},
+    room_in_use: {400, "M_ROOM_IN_USE", "The room is already in use."},
     unknown_token: {401, "M_UNKNOWN_TOKEN", "Invalid access token."},
     missing_token: {401, "M_MISSING_TOKEN", "Access token required."},
     not_found: {404, "M_NOT_FOUND", "The requested resource was not found."},