feat: expand list of terminal emulators that support truecolor

[bashbunni]

Carlos mentioned that there's a spot in termenv that checks the type of emulator used by the client to determine truecolor compatibility. Right now it's only checking a few, but termstandard has a much longer list of emulators that support truecolor that could be useful in this case.

https://github.com/termstandard/colors?tab=readme-ov-file#fully-supporting