fix:[#420] abort export if bin in $PATH

[jardon]

• abort if bin or output in $PATH
• en translation for abort message

$ ./apx snapcraft export -b ls

Error: Binary already exists on the host.
Usage:
  apx snapcraft export [flags]

Flags:
  -a, --app-name string     The name of the application to export.
  -b, --bin string          The name of the binary to export.
  -o, --bin-output string   Path of the binary output (default: ~/.local/bin/).
  -h, --help                help for export

  ERROR   Binary already exists on the host.

closes #420

[axtloss]

We didn't agree on any way to solve the issue yet, currently there are multiple solutions proposed, we should wait until we agree on a solution first