Implement collapsible panels for the new room list (#32742)

* Add `react-resizable-panels` library

* Implement a custom SeparatorView

* Add a `LeftResizablePanelView`

* Add a custom `GroupView`

* Export everything from shared-components

* Make it possible to track width/collapse state through settings

* Add a view model to drive the views

* Render views without disrupting the old room list

* Fix lint error

* Disable user interaction on collapsed panel

* Prevent widgets fron hijacking pointer events

* Expand to full width on separator click

* Separator should be shown when focused via keyboard

* Update tests

* Use data-attribute for hover

* Write stories for SeperatorView

* Write vite tests for SeparatorView

* Write tests for LeftResizablePanelView

* More tests

* Fix lint errors

* Fix flakey border on the roomlst

* Fix storybook axe violation

* Update snapshots

* Fix playwright tests

* Fix sonarcloud issues

* Use translated string

* Add better js-doc comments

* Rename `ResizerSnapshot` to `ResizerViewSnapshot`

* Externalize react-resizable-panels

* Link figma designs to stories

* Write playwright tests

* Update screenshots

* Fix lint errors

* Update more screenshots

* Update more screenshots

* Fix flaky toast test

* Update apps/web/playwright/e2e/crypto/toasts.spec.ts

Co-authored-by: Andy Balaam <andy.balaam@matrix.org>

* Fix indentation

---------

Co-authored-by: Andy Balaam <andy.balaam@matrix.org>

packages/shared-components/vite.config.ts

@@ -25,7 +25,12 @@ export default defineConfig({
         rolldownOptions: {
             // make sure to externalize deps that shouldn't be bundled
             // into your library
-            external: ["@vector-im/compound-design-tokens", "@vector-im/compound-web", "react-virtuoso"],
+            external: [
+                "@vector-im/compound-design-tokens",
+                "@vector-im/compound-web",
+                "react-virtuoso",
+                "react-resizable-panels",
+            ],
             plugins: [
                 esmExternalRequirePlugin({
                     external: ["react", "react-dom"],