MM-56630 Scroll Fix of center panel (#30144)

* pageup/pagedown button scroll for center post-list

* revert package.json

* changing id, using ? and returning in keyHandler

* added e2e test for pageup/pagedown scroll

* Fix dynamic-virtualized-list not being in lockfile and update path

Moving the package under the MM namespace wasn't necessary, but it stops
some warnings from NPM.

* Move E2E test from Cypress to Playwright

Cypress's cy.type doesn't seem to properly trigger browser functions
because it doesn't seem to use native keyboard events. A newer version
of Cypress has a new cy.press method which is supposed to use native
keyboard events, but it also only supports the tab key currently, so it
wouldn't be useful here.

* Fix new test on iPad

* Add page up/down support to RHS and Threads view

* Update type definitions for dynamic-virtualized-list

---------

Co-authored-by: Harrison Healey <harrisonmhealey@gmail.com>

e2e-tests/playwright/lib/src/ui/components/channels/post.ts

@@ -51,6 +51,12 @@ export default class ChannelsPost {
         return this.profileIcon.getByAltText(`${username} profile image`);
     }
 
+    async openRhs() {
+        await this.container.hover();
+        await this.postMenu.toBeVisible();
+        await this.postMenu.reply();
+    }
+
     /**
      * Clicks on the deleted post's remove 'x' button.
      * Also verifies that the post is a deleted post.