Feature: As an end-user, I should be able to see the list of agents in the widget. (#461)

Co-authored-by: Pranav Raj S <pranavrajs@gmail.com>

app/views/api/v1/widget/inbox_members/index.json.jbuilder

@@ -1,5 +1,6 @@
 json.payload do
   json.array! @inbox_members do |inbox_member|
+    json.id inbox_member.user.id
     json.name inbox_member.user.name
     json.avatar_url inbox_member.user.avatar_url
     json.availability_status inbox_member.user.availability_status