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/views/PreChatForm.vue

@@ -1,4 +1,5 @@
 <script>
+import { mapActions } from 'vuex';
 import PreChatForm from '../components/PreChat/Form.vue';
 import configMixin from '../mixins/configMixin';
 import routerMixin from '../mixins/routerMixin';
@@ -19,6 +20,8 @@ export default {
     emitter.off(ON_CONVERSATION_CREATED, this.handleConversationCreated);
   },
   methods: {
+    ...mapActions('conversation', ['clearConversations']),
+    ...mapActions('conversationAttributes', ['clearConversationAttributes']),
     handleConversationCreated() {
       // Redirect to messages page after conversation is created
       this.replaceRoute('messages');
@@ -48,6 +51,8 @@ export default {
           },
         });
       } else {
+        this.clearConversations();
+        this.clearConversationAttributes();
         this.$store.dispatch('conversation/createConversation', {
           fullName: fullName,
           emailAddress: emailAddress,