feat: UI part for A/V moderation. (#9195)

* feat: Initial UI part for A/V moderation.

Based on https://github.com/jitsi/jitsi-meet/pull/7779

Co-authored-by: Gabriel Imre <gabriel.lucaci@8x8.com>

* feat: Hides context menu in p2p or only moderators in the meeting.

* feat: Show notifications on enable/disable.

* feat(moderation): Add buttons to participant list & notifications

* fix(moderation): Fix raised hand participant leaving

* feat(moderation): Add support for video moderation

* feat(moderation): Add mute all video to context menu

* feat(moderation): Redo participants list 'More menu'

* fix: Fixes clearing av_moderation table.

* fix: Start moderation context menu

* fix(moderation): Show notification if unapproved participant tries to start CS

Co-authored-by: Gabriel Imre <gabriel.lucaci@8x8.com>
Co-authored-by: Vlad Piersec <vlad.piersec@8x8.com>

react/features/notifications/components/web/NotificationButton.js

@@ -0,0 +1,52 @@
+// @flow
+
+import React, { useCallback } from 'react';
+import { useDispatch } from 'react-redux';
+
+type Props = {
+
+    /**
+     * Action to be dispatched on click.
+     */
+    action: Function,
+
+    /**
+     * The text of the button.
+     */
+    children: React$Node,
+
+    /**
+     * CSS class of the button.
+     */
+    className: string,
+
+    /**
+     * The `data-testid` used for the button.
+     */
+    testId: string,
+
+    /**
+     * The participant.
+     */
+    participant: Object
+}
+
+/**
+ * Component used to display an approve/reject button.
+ *
+ * @returns {React$Element<'button'>}
+ */
+export default function({ action, children, className, testId, participant }: Props) {
+    const dispatch = useDispatch();
+    const onClick = useCallback(() => dispatch(action(participant.id)), [ dispatch, participant ]);
+
+    return (
+        <button
+            className = { className }
+            data-testid = { testId }
+            onClick = { onClick }
+            type = 'button'>
+            { children }
+        </button>
+    );
+}