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/javascript/dashboard/store/modules/specs/agentBots/fixtures.js

@@ -1,15 +1,35 @@
 export const agentBotRecords = [
   {
+    account_id: 1,
     id: 11,
     name: 'Agent Bot 11',
     description: 'Agent Bot Description',
-    type: 'csml',
+    bot_type: 'webhook',
+    thumbnail: 'https://example.com/thumbnail.jpg',
+    bot_config: {},
+    outgoing_url: 'https://example.com/outgoing',
+    access_token: 'hN8QwG769RqBXmme',
+    system_bot: false,
   },
 
   {
+    account_id: 1,
     id: 12,
     name: 'Agent Bot 12',
     description: 'Agent Bot Description 12',
-    type: 'csml',
+    bot_type: 'webhook',
+    thumbnail: 'https://example.com/thumbnail.jpg',
+    bot_config: {},
+    outgoing_url: 'https://example.com/outgoing',
+    access_token: 'hN8QwG769RqBXmme',
+    system_bot: false,
   },
 ];
+
+export const agentBotData = {
+  name: 'Test Bot',
+  description: 'Test Description',
+  outgoing_url: 'https://test.com',
+  bot_type: 'webhook',
+  avatar: new File([''], 'filename'),
+};