fix: Prevent reopening a resolved conversation (#11168)

# Pull Request Template

## Description

This PR addresses the issue where navigating back and starting a new
conversation incorrectly shows the previous messages or message screen.

Fixes
https://linear.app/chatwoot/issue/CW-4169/prevent-continue-conversation-in-previously-resolved-conversation

## Type of change

- [x] Bug fix (non-breaking change which fixes an issue)

## How Has This Been Tested?

### Loom video
**Before**

https://www.loom.com/share/18172a3b26ff4e8faf8e1c3c1a0ba279?sid=ffbda52a-93e1-400f-bedc-17b925bae4d3

**After**

https://www.loom.com/share/584177d411424ad38c6812be868eb060?sid=fe5e771a-3faa-4c14-a5fe-918a3ccdb408

## 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
- [ ] 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: Pranav <pranav@chatwoot.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/javascript/widget/components/ChatFooter.vue

@@ -55,15 +55,8 @@ export default {
     emitter.on(BUS_EVENTS.TOGGLE_REPLY_TO_MESSAGE, this.toggleReplyTo);
   },
   methods: {
-    ...mapActions('conversation', [
-      'sendMessage',
-      'sendAttachment',
-      'clearConversations',
-    ]),
-    ...mapActions('conversationAttributes', [
-      'getAttributes',
-      'clearConversationAttributes',
-    ]),
+    ...mapActions('conversation', ['sendMessage', 'sendAttachment']),
+    ...mapActions('conversationAttributes', ['getAttributes']),
     async handleSendMessage(content) {
       await this.sendMessage({
         content,
@@ -84,8 +77,6 @@ export default {
       this.inReplyTo = null;
     },
     startNewConversation() {
-      this.clearConversations();
-      this.clearConversationAttributes();
       this.replaceRoute('prechat-form');
       IFrameHelper.sendMessage({
         event: 'onEvent',