chore: Replace messageMixing with useMessage composable [CW-3475] (#9942)

# Pull Request Template

## Description

Replaces the messageMixin with the new useMessage composable

Fixes
https://linear.app/chatwoot/issue/CW-3475/rewrite-messagemixin-mixin-to-a-composable

## Type of change

Please delete options that are not relevant.

- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality not to work as expected)
- [ ] This change requires a documentation update

app/javascript/widget/components/AgentMessage.vue

@@ -9,7 +9,7 @@ import FileBubble from 'widget/components/FileBubble.vue';
 import Thumbnail from 'dashboard/components/widgets/Thumbnail.vue';
 import { MESSAGE_TYPE } from 'widget/helpers/constants';
 import configMixin from '../mixins/configMixin';
-import messageMixin from '../mixins/messageMixin';
+import { useMessage } from '../composables/useMessage';
 import { isASubmittedFormMessage } from 'shared/helpers/MessageTypeHelper';
 import darkModeMixin from 'widget/mixins/darkModeMixin.js';
 import ReplyToChip from 'widget/components/ReplyToChip.vue';
@@ -28,7 +28,7 @@ export default {
     MessageReplyButton,
     ReplyToChip,
   },
-  mixins: [configMixin, messageMixin, darkModeMixin],
+  mixins: [configMixin, darkModeMixin],
   props: {
     message: {
       type: Object,
@@ -39,6 +39,15 @@ export default {
       default: () => {},
     },
   },
+  setup(props) {
+    const { messageContentAttributes, hasAttachments } = useMessage(
+      props.message
+    );
+    return {
+      messageContentAttributes,
+      hasAttachments,
+    };
+  },
   data() {
     return {
       hasImageError: false,

app/javascript/widget/components/UserMessage.vue

@@ -6,7 +6,7 @@ import VideoBubble from 'widget/components/VideoBubble.vue';
 import FluentIcon from 'shared/components/FluentIcon/Index.vue';
 import FileBubble from 'widget/components/FileBubble.vue';
 import { messageStamp } from 'shared/helpers/timeHelper';
-import messageMixin from '../mixins/messageMixin';
+import { useMessage } from '../composables/useMessage';
 import ReplyToChip from 'widget/components/ReplyToChip.vue';
 import DragWrapper from 'widget/components/DragWrapper.vue';
 import { BUS_EVENTS } from 'shared/constants/busEvents';
@@ -25,7 +25,6 @@ export default {
     ReplyToChip,
     DragWrapper,
   },
-  mixins: [messageMixin],
   props: {
     message: {
       type: Object,
@@ -36,6 +35,12 @@ export default {
       default: () => {},
     },
   },
+  setup(props) {
+    const { hasAttachments } = useMessage(props.message);
+    return {
+      hasAttachments,
+    };
+  },
   data() {
     return {
       hasImageError: false,