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/components/layout/config/sidebarItems/settings.js

@@ -127,7 +127,6 @@ const settings = accountId => ({
       meta: {
         permissions: ['administrator'],
       },
-      globalConfigFlag: 'csmlEditorHost',
       toState: frontendURL(`accounts/${accountId}/settings/agent-bots`),
       toStateName: 'agent_bots',
       featureFlag: FEATURE_FLAGS.AGENT_BOTS,