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>

app/controllers/api/v1/accounts/agent_bots_controller.rb

@@ -37,7 +37,7 @@ class Api::V1::Accounts::AgentBotsController < Api::V1::Accounts::BaseController
   end
 
   def permitted_params
-    params.permit(:name, :description, :outgoing_url, :avatar, :avatar_url, :bot_type, bot_config: [:csml_content])
+    params.permit(:name, :description, :outgoing_url, :avatar, :avatar_url, :bot_type, bot_config: {})
   end
 
   def process_avatar_from_url