Feature/add vui as webui flavor (#609)

* Remove unused "downloadAhead" function

* [Codegen] Update generated files

* Add "VUI" as webui flavor

* Add info about changing the webUI channel or flavor

src/lib/graphql/mutations/DownloaderMutation.ts

@@ -134,11 +134,3 @@ export const STOP_DOWNLOADER = gql`
         }
     }
 `;
-
-export const DOWNLOAD_AHEAD = gql`
-    mutation DOWNLOAD_AHEAD($input: DownloadAheadInput!) {
-        downloadAhead(input: $input) {
-            clientMutationId
-        }
-    }
-`;