Handle empty source uploads in dedicated way

[de-jcup]

Checkmarx adapter does currently fail when source files are empty.

E.g. :

Caused by: com.daimler.sechub.adapter.AdapterException: __[SECHUB-UID:18b606d1-6729-486f-83d1-50ea0c7634ed]__ CheckmarxAdapterV1:The queuing has failed:Failed to start scanning due to one of following reasons: source folder is empty, all source files are of an unsupported language or file format

On response we got only one finding with text: "description" : "Security product 'CHECKMARX' failed, so cannot give a correct answer.",

We could handle this in future in one of the following variants:

1. Show a dedicated finding (warning) that no sources where uploaded and do not call any product . So no matter which product this would be always same.
2. Let it as is - means being product specific response.... not nice
3. SecHub accepts this always as "green" - no source, no cry... So no matter which product this would be always same.

[Jeeppler]

@de-jcup Is this still an issue?