SearchForInstance with study UID

Qido define 3 request type for SearchForInstances : 
- {SERVICE}/studies/{StudyInstanceUID}/series/{SeriesInstanceUID}/instances[?query]
- {SERVICE}/studies/{StudyInstanceUID}/instances[?query]
- {SERVICE}/instances[?query]

Dcm4chee-arc was missing the second one.

P.S. 1: I don't know if this is the right project for pull request as dcm4chee-arc-cdi seems more up to date.
P.S. 2: I don't know why there is a commit from @gunterze on this pull request, I was unable to create one without it.