Fix some of the Javascript linting issues, as well as bugs and unneeded divergences with upstream (#2208)

* Run eslint --fix

* Fix linting issues in video player and reduce divergences with upstream

This includes a behavior change of not auto-looping videos anymore. I don't
remember loops being ever intended, and they have been removed from upstream
a while ago, but we somehow missed the change.

* Fix lint issues in `app/javascript/flavours/glitch/selectors/index.js`

Those were basically caused by dead code that isn't present upstream, so
that brings us closer to upstream as well.

* Fix linting issue and bug in streaming/index.js

* Fix linting issues in config/webpack/shared.js

* Fix unused import in flavours/glitch/features/ui/index.js

* Fix linting issues and reduce divergences from upstream in flavours/glitch/features/ui/components/video_modal.jsx

* Fix linting issues in flavours/glitch/reducers

* Fix linting issues in glitch-soc onboarding modal

* Fix linting issues in flavours/glitch/features/ui/components/navigation_panel.jsx

* Remove dead code for unused local setting navbar_under

* Fix various linting issues

* Fix linting issues in flavours/glitch/components/scrollable_list.jsx and reduce divergences with upstream

streaming/index.js

@@ -373,7 +373,6 @@ const startServer = async () => {
   const channelNameFromPath = req => {
     const { path, query } = req;
     const onlyMedia = isTruthy(query.only_media);
-    const allowLocalOnly = isTruthy(query.allow_local_only);
 
     switch (path) {
     case '/api/v1/streaming/user':
@@ -990,7 +989,7 @@ const startServer = async () => {
     case 'public:media':
       resolve({
         channelIds: ['timeline:public:media'],
-        options: { needsFiltering: true, allowLocalOnly: isTruthy(query.allow_local_only) },
+        options: { needsFiltering: true, allowLocalOnly: isTruthy(params.allow_local_only) },
       });
 
       break;