feat: Move timeMixin to a helper (#9799)

# Pull Request Template

## Description

This PR will replace the usage of `timeMixin` with `timeHelper`

Fixes
https://linear.app/chatwoot/issue/CW-3451/move-time-mixin-to-a-helper

## Type of change

- [x] New feature (non-breaking change which adds functionality)

## How Has This Been Tested?

Please refer to this issue description.
https://linear.app/chatwoot/issue/CW-3451/move-time-mixin-to-a-helper

## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] 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/bubble/Actions.vue

@@ -77,10 +77,10 @@
 import { MESSAGE_TYPE, MESSAGE_STATUS } from 'shared/constants/messages';
 import inboxMixin from 'shared/mixins/inboxMixin';
 import { mapGetters } from 'vuex';
-import timeMixin from '../../../../mixins/time';
+import { messageTimestamp } from 'shared/helpers/timeHelper';
 
 export default {
-  mixins: [inboxMixin, timeMixin],
+  mixins: [inboxMixin],
   props: {
     sender: {
       type: Object,
@@ -159,7 +159,7 @@ export default {
       return MESSAGE_STATUS.SENT === this.messageStatus;
     },
     readableTime() {
-      return this.messageTimestamp(this.createdAt, 'LLL d, h:mm a');
+      return messageTimestamp(this.createdAt, 'LLL d, h:mm a');
     },
     screenName() {
       const { additional_attributes: additionalAttributes = {} } =