feat: Add APIs to manage custom roles in Chatwoot (#9995)

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

spec/enterprise/models/custom_role_spec.rb

@@ -0,0 +1,12 @@
+require 'rails_helper'
+
+RSpec.describe CustomRole, type: :model do
+  describe 'associations' do
+    it { is_expected.to belong_to(:account) }
+    it { is_expected.to have_many(:account_users).dependent(:nullify) }
+  end
+
+  describe 'validations' do
+    it { is_expected.to validate_presence_of(:name) }
+  end
+end