Add artifact name as argument but enforce a positional default

[AlexDCraig]

The purpose of this PR is to allow for downstream dependencies to have custom report/artifact names. The default argument is to make sure packages dependent on this library that I am not aware of do not break from the introduction of this small feature.

[thc202]

Thank you!

[kingthorin]

Good to merge?

[thc202]

I think so, the changes look ok to me.

[kingthorin]

Just wasn’t sure if it needed to be coordinated with anything else.

[thc202]

Changes in this lib are fine to merge anytime.

[tony]

For later (this would be breaking and I don't want to delay a new release):

In a future version we may want to move artifactName to a new options object (similar to @actions/artifact's params) to make params more readable in the future

e.g. actionHelper.uploadArtifacts(workSpace, mdReportName, jsonReportName, htmlReportName, {artifactName})

That way options will be more easy to manage and we won't have the dreaded case where an additional position argument forces future downstream users pass undefined to fill 'zap_scan': actionHelper.uploadArtifacts(workSpace, mdReportName, jsonReportName, htmlReportName, undefined, newParam)