DIFF_RS: return super set of attributes defined by QIDO-RS Study Result Attributes

[gunterze]

Particularly, if Query Parameter includefield=all and if an Attribute Set all configured, return the union of that Attribute Set with the Study Result Attributes defined by QIDO-RS.

Enables to return (0008,0061) Modalities in Study without having to add it in the all Attribute Set - which would define it also as compare Attribute for Query Parameter comparefield=all - which is typically not intended, because the order of multiple modality values may vary returned from the different archives, so it may cause to raise such studies as different.