feat(local-recordings) drop old "local recordings" implementation

It's about to become very confusing, since we are going to add actual
local recordings with video.

This feature was never fully finalizeed since it required manual
processing of the files, as they were not uploaded anywhere.

In addition, unless one opens the local audio device without any audio
processing first, any tracks opened later will have audio proceessing
turned on, something not desirable for the scenario this feature was
designed for in the first place: podcasts.

This feature will likely come back as a JaaS demo / MVP where the local
recording is made outside of the Jitsi Meet iframe.

css/main.scss

@@ -40,7 +40,6 @@ $flagsImagePath: "../images/";
 @import 'modals/invite/info';
 @import 'modals/screen-share/share-audio';
 @import 'modals/screen-share/share-screen-warning';
-@import 'modals/local-recording/local-recording';
 @import 'videolayout_default';
 @import 'notice';
 @import 'subject';