Allow extra options for SSC export to be specified, for example to use a non-default filter set

[rsenden]

Enhancement Request

The GitHub Action currently only passes the --av and -f options to the fcli ssc action run github-sast-report command, to specify application version and output file name. The fcli action also supports other options though; users may in particular be interested in specifying a non-default filter set through the --fs option. Just like we have for other commands, the GitHub Action should support an EXTRA_EXPORT_OPTS environment variable.

Note that for now, this is not relevant for the FoD-specific export action, as the fcli fod action run github-sast-report doesn't support any extra options.