Credential Store for jobs - @attachment property should be supported

Current Situation

• The Credential Store interface for jobs supports the query parameter attachment=1 to read a attachment field
  • e.g: cs://server/SFTP/myserver@privat.dsa?file=config/credential_store.kdbx&attachment=1
• The Credential Store interface for YADE allows to use a @attachment property to read the first attachment
  • e.g: cs://server/SFTP/myserver@attachment?file=config/credential_store.kdbx
  • in this case the Credential Store interface always returns the first attachment - independently of the attachment name.

Desired Behaviour

• The Credential Store interface for jobs should support the @attachment property to read the first attachment too