Clean up references to `scala-cli` in SIP mode

[Gedochao]

Describe what needs to be done and why
When in SIP mode, the help sub-command and other outputs (warnings and such) should never refer to scala-cli, and instead use the actual binary name.

Is your feature request related to a past ticket or discussion?
scala/improvement-proposals#46

Additional context
Referring to Scala CLI (as we do in a number of spots) should still be alright.