Instead of half-running PowerShell with -noninteractive (and expecting
the user debugging to enter more arguments), the latest stable version
of VS Code allows us to launch an external console. This requires either
Gnome Terminal or xterm (sadly not Xfce Terminal), but given either (and
xterm is almost always available to install), we can now launch an
interactive PowerShell session to debug.
This enables building PowerShell through VS Code. The build task
launches the installed version of PowerShell and runs
`Start-PSBuild` (after importing the module).
This enables a `launch` debug task to immediately debug the `powershell`
process, without having to attach to an external process.
The defaults of `justMyCode` and `stopAtEntry` have been reversed, so
that all code is debugged, and the process is stopped at entry for
easier debugging.
Note that an interactive PowerShell process requires access to `stdin`,
which the debug console does not provide, so once it requests access,
`System.Console` will throw a (correct) exception.
