dcm4che-tool-dcmqrscp: optionally accept C-FIND, C-GET and C-MOVE RQs with missing Unique Key Attribute for levels above the Query/Retrieve level even if no Relational-Queries/Retrieve was negotiated

[gunterze]

New option:

    --relational-lenient                accept C-FIND, C-GET and C-MOVE
                                        RQs with missing Unique Key
                                        Attribute for levels above the
                                        Query/Retrieve level even if no
                                        Relational-Queries/Retrieve was
                                        negotiated

Missing Unique Key Attributes are logged, e.g.:

12:09:35,623 DEBUG - DCM4CHEE<-TEST(1) >> 1:C-FIND-RQ Dataset receiving...
12:09:35,623 DEBUG - Dataset:
(0008,0018) UI [1.2.840.113619.2.55.1.1762927524.2188.1148396481.959.227] SOPI
(0008,0052) CS [IMAGE] QueryRetrieveLevel

12:09:35,624 INFO  - Missing StudyInstanceUID (0020,000D) in Query/Retrieve Identifier
12:09:35,624 INFO  - Missing SeriesInstanceUID (0020,000E) in Query/Retrieve Identifier