chore: Audit message characters across all channels (#11343)

- Audited message characters across all channels.
- Replaced `isAInstagramChannel` with `isAnInstagramChannel`

app/javascript/shared/helpers/MessageTypeHelper.js

@@ -4,8 +4,20 @@ export const isASubmittedFormMessage = (message = {}) =>
 
 export const MESSAGE_MAX_LENGTH = {
   GENERAL: 10000,
-  FACEBOOK: 1000,
+  // https://developers.facebook.com/docs/messenger-platform/reference/send-api#request
+  FACEBOOK: 2000,
+  // https://developers.facebook.com/docs/instagram-platform/instagram-api-with-instagram-login/messaging-api#send-a-text-message
+  INSTAGRAM: 1000,
+  // https://www.twilio.com/docs/glossary/what-sms-character-limit
   TWILIO_SMS: 320,
+  // https://help.twilio.com/articles/360033806753-Maximum-Message-Length-with-Twilio-Programmable-Messaging
   TWILIO_WHATSAPP: 1600,
+  // https://developers.facebook.com/docs/whatsapp/cloud-api/reference/messages#text-object
+  WHATSAPP_CLOUD: 4096,
+  // https://support.bandwidth.com/hc/en-us/articles/360010235373-What-are-Bandwidth-s-SMS-character-limits-and-concatenation-practices
+  BANDWIDTH_SMS: 160,
+  // https://core.telegram.org/bots/api#sendmessage
+  TELEGRAM: 4096,
+  LINE: 2000,
   EMAIL: 25000,
 };

app/javascript/shared/mixins/inboxMixin.js

@@ -121,7 +121,7 @@ export default {
         this.isATwilioWhatsAppChannel
       );
     },
-    isAInstagramChannel() {
+    isAnInstagramChannel() {
       return this.channelType === INBOX_TYPES.INSTAGRAM;
     },
   },