feat: Add flag to read from file/stdin

[Its-Just-Nans]

The --files0-from=- option of du

[rindeal]

I'm personally in favour of --files-from and --files0-from, but if @bootandy wants a stdin only feature, then it should be enabled just by passing a single - target dir, which is the commonly used CLI semantic in such case.

[Its-Just-Nans]

Yes, you're right !

Note that this still has an issue: fixed below

if someone does dust --files0-from=- without stdin, dust will block on the stdin

And you can leave with CTRL+D or kill the program

[Its-Just-Nans]

Okay I made a fix using an Arc<AtomicBool> to check if we need to abort

[bootandy]

ok, if you think people will use this, i'll include it.