Use upstream's settings for CW auto-expand and column swiping (#1770)

* Use Mastodon server-side settings for automatically expanding toots with CWs

* Add modal warning about settings changes

* Use Mastodon server-side settings for disabling swiping

app/javascript/flavours/glitch/util/content_warning.js

@@ -1,5 +1,7 @@
+import { expandSpoilers } from 'flavours/glitch/util/initial_state';
+
 export function autoUnfoldCW (settings, status) {
-  if (!settings.getIn(['content_warnings', 'auto_unfold'])) {
+  if (!expandSpoilers) {
     return false;
   }