feat: Replace alertMixin usage with useAlert (#9793)

# Pull Request Template

## Description

This PR will replace the usage of `alertMixin` from the code base with
the `useAlert` composable.

Fixes
https://linear.app/chatwoot/issue/CW-3462/replace-alertmixin-usage-with-usealert

## Type of change

- [x] Breaking change (fix or feature that would cause existing
functionality not to work as expected)

## How Has This Been Tested?

Please refer this issue description

https://linear.app/chatwoot/issue/CW-3462/replace-alertmixin-usage-with-usealert


## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [ ] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

---------

Co-authored-by: Sojan Jose <sojan@pepalo.com>

app/javascript/dashboard/components/widgets/conversation/specs/MoreActions.spec.js

@@ -85,11 +85,11 @@ describe('MoveActions', () => {
     it('shows alert', async () => {
       await moreActions.find('button:first-child').trigger('click');
 
-      expect(emitter.emit).toBeCalledWith(
-        'newToastMessage',
-        'This contact is blocked successfully. You will not be notified of any future conversations.',
-        undefined
-      );
+      expect(emitter.emit).toBeCalledWith('newToastMessage', {
+        message:
+          'This contact is blocked successfully. You will not be notified of any future conversations.',
+        action: null,
+      });
     });
   });
 
@@ -111,11 +111,10 @@ describe('MoveActions', () => {
     it('shows alert', async () => {
       await moreActions.find('button:first-child').trigger('click');
 
-      expect(emitter.emit).toBeCalledWith(
-        'newToastMessage',
-        'This contact is unblocked successfully.',
-        undefined
-      );
+      expect(emitter.emit).toBeCalledWith('newToastMessage', {
+        message: 'This contact is unblocked successfully.',
+        action: null,
+      });
     });
   });
 });