Persist UI settings, add missing localizations for German

app/views/home/initial_state.json.rabl

@@ -0,0 +1,24 @@
+object false
+
+node(:meta) {
+  {
+    access_token: @token,
+    locale: I18n.locale,
+    me: current_account.id,
+  }
+}
+
+node(:compose) {
+  {
+    me: current_account.id,
+    private: current_account.locked?,
+  }
+}
+
+node(:accounts) {
+  {
+    current_account.id => partial('api/v1/accounts/show', object: current_account),
+  }
+}
+
+node(:settings) { @web_settings }