fix: redirect to last active conversation when social channel opened in messenger

[domw30]

What does this do?

• Added path checking in performValidateActiveConversation saga to detect if we're in messenger app, and if so, redirect to last active conversation when attempting to open a social channel.

Why are we making this change?

• To prevent social channels from being opened in messenger app since they should only be viewed in the feed app, while maintaining a smooth user experience by showing their last active messenger conversation instead.

How do I test this?

• run tests as usual
• run ui and test

Key decisions and Risk Assessment:

Things to consider:

1. How will this affect security?
2. How will this affect performance?
3. Does this change any APIs?