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/javascript/dashboard/store/modules/specs/agentBots/mutations.spec.js

@@ -51,4 +51,16 @@ describe('#mutations', () => {
       expect(state.agentBotInbox).toEqual({ 3: 2 });
     });
   });
+  describe('#UPDATE_AGENT_BOT_AVATAR', () => {
+    it('update agent bot avatar', () => {
+      const state = { records: [agentBotRecords[0]] };
+      mutations[types.UPDATE_AGENT_BOT_AVATAR](state, {
+        id: 11,
+        thumbnail: 'https://example.com/thumbnail.jpg',
+      });
+      expect(state.records[0].thumbnail).toEqual(
+        'https://example.com/thumbnail.jpg'
+      );
+    });
+  });
 });