furyctl-ng: dump command --outdir param check

[davide-rossi-ce]

verified on furyctl 0.26.1

The --outdir behaviour of the dump command( that writes directly to the directory passed as --outdir param ) is different from other commands ( that instead work on the .furyctl child dir of --outdir ).

Also, the dump command seems to wipe the --outdir directory before doing any other action.

This can lead to mistakenly wipe the project dir.
Maybe a check could be done to verify if the dump outdir is empty,
or maybe write to another child dir ( es. outdir/.furyctl/dump ).