Add config setting to disable bulk unverified sessions nag (#9657)

* test bulk unverified sessions toast behaviour

* unverified sessions toast text tweak

* only show bulk unverified sessions toast when current device is verified

* add Setting for BulkUnverifiedSessionsReminder

* add build config for BulkUnverifiedSessionsReminder

* add more assertions for show/hide toast, fix strict errors

* fix strict error

src/settings/Settings.tsx

@@ -1149,6 +1149,10 @@ export const SETTINGS: {[setting: string]: ISetting} = {
         supportedLevels: LEVELS_UI_FEATURE,
         default: true,
     },
+    [UIFeature.BulkUnverifiedSessionsReminder]: {
+        supportedLevels: LEVELS_UI_FEATURE,
+        default: true,
+    },
 
     // Electron-specific settings, they are stored by Electron and set/read over an IPC.
     // We store them over there are they are necessary to know before the renderer process launches.