Only query DIM providers on query/retrieve and move

[Enet4]

Follow-up on #122. Dicoogle 3 has a new multi-value property for listing the query providers which provide DICOM meta-data, but this has not been considered in all places of the archive yet.

• By default, the QueryRetrieve and Move SCP should perform queries only to the query providers named in the archive/dim-provider element of the server settings (confs/server.xml), except if this list of providers is empty, which in that case it may query all enabled query providers.
  • SearchDicomResult is a relevant component here.