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

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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>

app/controllers/dashboard_controller.rb

@@ -36,7 +36,7 @@ class DashboardController < ActionController::Base
       'LOGOUT_REDIRECT_LINK',
       'DISABLE_USER_PROFILE_UPDATE',
       'DEPLOYMENT_ENV',
-      'CSML_EDITOR_HOST', 'INSTALLATION_PRICING_PLAN'
+      'INSTALLATION_PRICING_PLAN'
     ).merge(app_config)
   end