[Feature] Add whitelisted messages or substrings of messages to show that are being hidden by this addon

[Kryllo]

I was wondering if it were possible to add the ability to add in substrings of messages that you want to show in the chat frames. An example I have is I'm using the Vendor addon which has a chat message output when you vendor or destroy items based on critera. However, I noticed that messaages weren't appearing. I disabled Chat Cleaner and the messages from Vendor started appearing.