Add the option for --extract_license

Add text for the usage.

Add code for the command line that use '--extract_license"

Add code to check the required api field for the --extract_license
Implement the "extract_license" from DJE feature.

This will now extract the license from DJE License Library based on the 'dje_license_key' and create a <dje_license_key>.LICENSE side by side with the .ABOUT file