feat: Added the ability to create Instagram channel (#11182)

This PR is part of https://github.com/chatwoot/chatwoot/pull/11054 to
make the review cycle easier.

spec/factories/channel/channel_instagram.rb

@@ -6,6 +6,21 @@ FactoryBot.define do
     expires_at { 60.days.from_now }
     updated_at { 25.hours.ago }
 
+    before :create do |channel|
+      WebMock::API.stub_request(:post, "https://graph.instagram.com/v22.0/#{channel.instagram_id}/subscribed_apps")
+                  .with(query: {
+                          access_token: channel.access_token,
+                          subscribed_fields: %w[messages message_reactions messaging_seen]
+                        })
+                  .to_return(status: 200, body: '', headers: {})
+
+      WebMock::API.stub_request(:delete, "https://graph.instagram.com/v22.0/#{channel.instagram_id}/subscribed_apps")
+                  .with(query: {
+                          access_token: channel.access_token
+                        })
+                  .to_return(status: 200, body: '', headers: {})
+    end
+
     after(:create) do |channel|
       create(:inbox, channel: channel, account: channel.account)
     end