feat(usersettings): add separate setting for streaming region (#993)

* feat: add separate setting for streaming region

Currently, the "Currently Streaming On" information is based on the Discover Region setting. This PR
adds a new setting to specify which region should be used to display the streaming region.

re #890

* fix: add missing newline

* fix: rename migration function

src/pages/_app.tsx

@@ -192,7 +192,8 @@ CoreApp.getInitialProps = async (initialProps) => {
     movie4kEnabled: false,
     series4kEnabled: false,
     localLogin: true,
-    region: '',
+    discoverRegion: '',
+    streamingRegion: '',
     originalLanguage: '',
     mediaServerType: MediaServerType.NOT_CONFIGURED,
     partialRequestsEnabled: true,