chore: Add new tab and copy link to conversation context menu (#12089)

# Pull Request Template

## Description

This PR includes the following enhancements to the conversation card
context menu:

1. **Added "Open in New Tab" and "Copy Conversation Link" options.**
* "Open in New Tab" allows users to quickly open a conversation in a
separate browser tab.
* "Copy Conversation Link" copies the conversation URL to the clipboard
for easy sharing.

2. **Enabled the context menu in Previous Conversations card** with
support for these two options.

Fixes
https://linear.app/chatwoot/issue/CW-4722/cannot-open-previous-conversations-in-a-new-tab

## Type of change

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

## How Has This Been Tested?

### Loom video

https://www.loom.com/share/37b45d23c6804db292568d093b645ac0?sid=c3105971-f938-41bd-9f52-0f00d419d1b3


## 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
- [ ] 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>

app/javascript/dashboard/i18n/locale/en/conversation.json

@@ -144,6 +144,9 @@
       "AGENTS_LOADING": "Loading agents...",
       "ASSIGN_TEAM": "Assign team",
       "DELETE": "Delete conversation",
+      "OPEN_IN_NEW_TAB": "Open in new tab",
+      "COPY_LINK": "Copy conversation link",
+      "COPY_LINK_SUCCESS": "Conversation link copied to clipboard",
       "API": {
         "AGENT_ASSIGNMENT": {
           "SUCCESFUL": "Conversation id {conversationId} assigned to \"{agentName}\"",