Refactor EventPreview to shared MVVM (#33646)

* Refactor EventPreview to shared MVVM

* Fix EventPreviewView export formatting

* Snapshots images for stories

* Deduplicate event preview formatting

* Handle event preview update failures

* Coalesce event preview updates

* Wait for event preview test expectations

apps/web/res/css/_components.pcss

@@ -255,7 +255,6 @@
 @import "./views/rooms/_EditMessageComposer.pcss";
 @import "./views/rooms/_EmojiButton.pcss";
 @import "./views/rooms/_EventBubbleTile.pcss";
-@import "./views/rooms/_EventPreview.pcss";
 @import "./views/rooms/_EventTile.pcss";
 @import "./views/rooms/_HistoryTile.pcss";
 @import "./views/rooms/_IRCLayout.pcss";

apps/web/res/css/views/rooms/_EventPreview.pcss

@@ -1,18 +0,0 @@
-/*
- * Copyright 2024 New Vector Ltd.
- * Copyright 2024 The Matrix.org Foundation C.I.C.
- *
- * SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
- * Please see LICENSE files in the repository root for full details.
- */
-
-.mx_EventPreview {
-    font: var(--cpd-font-body-sm-regular);
-    overflow: hidden;
-    text-overflow: ellipsis;
-    white-space: nowrap;
-
-    .mx_EventPreview_prefix {
-        font: var(--cpd-font-body-sm-semibold);
-    }
-}