Add ability to expand and collapse long quoted messages (#6701)

In case where we had a very long message the experience of going between 
messages to see the full quote isn't very nice on desktop, therefore this commit
adds a button with additional hotkey to normalize the experience a bit.

Fixes https://github.com/vector-im/element-web/issues/18884

src/i18n/strings/en_EN.json

@@ -1944,6 +1944,8 @@
     "Edit": "Edit",
     "Reply": "Reply",
     "Thread": "Thread",
+    "Collapse quotes │ ⇧+click": "Collapse quotes │ ⇧+click",
+    "Expand quotes │ ⇧+click": "Expand quotes │ ⇧+click",
     "Message Actions": "Message Actions",
     "Download %(text)s": "Download %(text)s",
     "Error decrypting attachment": "Error decrypting attachment",