[FEATURE] Expand ability to specify scanning parameters exclude and remove scanned results

[davidallendj]

When performing a scan, the user can specify the subnet(s) and host(s) to add, but cannot exclude host using a pattern. This could be expanded to allow excluding specific hosts or deleting hosts through the CLI after a scan is done. That way if a host is no longer needed to be managed later, deleting it provides a clear, straightforward way to remove it.

Migrated from https://github.com/bikeshack/magellan/issues/11