Make script loader v2 compatible with console

[bentsherman]

Spun off from #5937

The console runner used by nextflow console uses the ScriptLoader in a way that is not supported by the script loader v2 -- it is more surgical than what the v2 loader allows.

Either the script loader v2 should be modified to support the console, or the console should be phased out in favor of a command-line REPL (e.g. nf shell), which may be done as part of a CLI v2.