feat: add direct message link (#12138)

* feat: add direct message link

/message/:mid
add /:index? to chat routes
add copy link to chat messages
add messageCount to each room object
add infinitescroll in both directions to chat

* fix more tests

* test: more text fixes

* test: fix tests

* remove async

* dont crash if element not in dom

clamp scrollToIndex values to 0, msgCount

test/api.js

@@ -281,7 +281,7 @@ describe('API', async () => {
 		await flags.create('post', 2, unprivUid, 'sample reasons', Date.now()); // for testing flag notes (since flag 1 deleted)
 
 		// Create a new chat room
-		await messaging.newRoom(1, { uids: [2] });
+		await messaging.newRoom(adminUid, { uids: [unprivUid] });
 
 		// Create an empty file to test DELETE /files and thumb deletion
 		fs.closeSync(fs.openSync(path.resolve(nconf.get('upload_path'), 'files/test.txt'), 'w'));