Indicate unsaved changes in the terminal title

[adamjoer]

It would be helpful to indicate when the active document contains unsaved changes by showing an asterisk next to its filename in the terminal title.

This would be in-line with the behaviour of other editing software such as notepad:

https://github.com/user-attachments/assets/25a1b674-cdf2-4c5f-a4be-73c800148622