feat: Implement UI for Agent Bots in settings and remove CSML support (#11276)

- Add agent bots management UI in settings with avatar upload
- Enable agent bot configuration for all inbox types
- Implement proper CRUD operations with webhook URL support
- Fix agent bots menu item visibility in settings sidebar
- Remove all CSML-related code and features
- Add migration to convert existing CSML bots to webhook bots
- Simplify agent bot model and services to focus on webhook bots
- Improve UI to differentiate between system bots and account bots

## Video 





https://github.com/user-attachments/assets/3f4edbb7-b758-468c-8dd6-a9537b983f7d

---------

Co-authored-by: iamsivin <iamsivin@gmail.com>
Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: Pranav <pranav@chatwoot.com>

spec/jobs/agent_bots/csml_job_spec.rb

@@ -1,19 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe AgentBots::CsmlJob do
-  it 'runs csml processor service' do
-    event = 'message.created'
-    message = create(:message)
-    agent_bot = create(:agent_bot)
-    processor = double
-
-    allow(Integrations::Csml::ProcessorService).to receive(:new).and_return(processor)
-    allow(processor).to receive(:perform)
-
-    described_class.perform_now(event, agent_bot, message)
-
-    expect(Integrations::Csml::ProcessorService)
-      .to have_received(:new)
-      .with(event_name: event, agent_bot: agent_bot, event_data: { message: message })
-  end
-end