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

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

spec/enterprise/controllers/enterprise/api/v1/accounts/agents_controller_spec.rb

@@ -0,0 +1,24 @@
+require 'rails_helper'
+
+RSpec.describe 'Enterprise Agents API', type: :request do
+  let(:account) { create(:account) }
+  let(:admin) { create(:user, account: account, role: :administrator) }
+
+  describe 'PUT /api/v1/accounts/{account.id}/agents/:id' do
+    let(:other_agent) { create(:user, account: account, role: :agent) }
+    let!(:custom_role) { create(:custom_role, account: account) }
+
+    context 'when it is an authenticated administrator' do
+      it 'modified the custom role of the agent' do
+        put "/api/v1/accounts/#{account.id}/agents/#{other_agent.id}",
+            headers: admin.create_new_auth_token,
+            params: { custom_role_id: custom_role.id },
+            as: :json
+
+        expect(response).to have_http_status(:success)
+        expect(other_agent.account_users.first.reload.custom_role_id).to eq(custom_role.id)
+        expect(JSON.parse(response.body)['custom_role_id']).to eq(custom_role.id)
+      end
+    end
+  end
+end