Implement Scala CLI as the `scala` runner command

[Gedochao]

Finally, the time has come to bring SIP-46 to a closure and implement Scala CLI as the official runner command for the Scala 3 compiler.

Corresponding compiler issue

• https://github.com/scala/scala3/issues/20098

Relevant docs

• SIP-46 details
• experimental Scala CLI as scala installation
• migration from the old Scala runner (a guide)

Requirements

• [x] set up downloading of Scala CLI JVM launcher from GitHub VirtusLab/scala-cli
• [x] download library dependencies to the dist/target/pack in maven repo style
• [x] fix scripts to wrap Scala CLI launcher, setting both the local repo and default scala version launcher options
  • [x] update for windows (batch)
  • [x] update for linux/mac (bash)
• [x] run any existing legacy (old) scala runner tests against the Scala CLI launcher on the scala/scala3 CI
• [ ] use the Scala CLI launcher instead of the scala runner in official Scala 3 distributions
  • [x] coursier
  • [ ] brew
  • [x] SDKMAN

Potential follow-ups which are NOT included in this issue's scope

• including platform-specific native installations of Scala CLI in Scala 3 official distribution channels
  • this should be done alongside native distribution of scalac, scaladoc etc
• including Scala CLI in other Scala 3 installation methods (APT, winget, etc)