Adjust the Default Subject Line for Emailed Chat Transcripts

When customers choose to have their chat transcript emailed to them after chatting with us the email that they receive has a subject line of "chat transcript" which can't be edited.

We'd like to have the ability to customize this so that we can include our company name. For example, "Company Name Chat Transcript". It's common for companies to have a live chat system and it's unclear where the email is originating from at a glance with the current subject line.