feat: Support for Whatsapp Cloud API (#4938)

Ability to configure Whatsapp Cloud API Inboxes

fixes: #4712

spec/models/channel/whatsapp_spec.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Channel::Whatsapp do
+  describe 'validate_provider_config' do
+    let(:channel) { build(:channel_whatsapp, provider: 'whatsapp_cloud', account: create(:account)) }
+
+    it 'validates false when provider config is wrong' do
+      stub_request(:get, 'https://graph.facebook.com/v14.0//message_templates?access_token=test_key').to_return(status: 401)
+      expect(channel.save).to eq(false)
+    end
+
+    it 'validates true when provider config is right' do
+      stub_request(:get, 'https://graph.facebook.com/v14.0//message_templates?access_token=test_key')
+        .to_return(status: 200,
+                   body: { data: [{
+                     id: '123456789', name: 'test_template'
+                   }] }.to_json)
+      expect(channel.save).to eq(true)
+    end
+  end
+end