[IMPROVE] Check Livechat message length through REST API endpoint (#20366)

* Changed broken link for english

* checking msg len in api call

* Revert "Changed broken link for english"

This reverts commit 5c6e64cbe1.

* lint fixes

* if condn changes

Co-authored-by: Renato Becker <renato.augusto.becker@gmail.com>

app/livechat/server/api/v1/message.js

@@ -9,6 +9,7 @@ import { loadMessageHistory } from '../../../../lib';
 import { findGuest, findRoom, normalizeHttpHeaderData } from '../lib/livechat';
 import { Livechat } from '../../lib/Livechat';
 import { normalizeMessageFileUpload } from '../../../../utils/server/functions/normalizeMessageFileUpload';
+import { settings } from '../../../../settings/server';
 
 API.v1.addRoute('livechat/message', {
 	post() {
@@ -40,6 +41,10 @@ API.v1.addRoute('livechat/message', {
 				throw new Meteor.Error('room-closed');
 			}
 
+			if (settings.get('Livechat_enable_message_character_limit') && msg.length > parseInt(settings.get('Livechat_message_character_limit'))) {
+				throw new Meteor.Error('message-length-exceeds-character-limit');
+			}
+
 			const _id = this.bodyParams._id || Random.id();
 
 			const sendMessage = {