Add tomo projection images to mammo import extractor

[Ed McDonagh]

Hologic mammography digital breast tomosynthesis objects have a corresponding object that contains the projection images. These are of class UID 1.2.840.10008.5.1.4.1.1.7 which is secondary capture, but with a modality of MG.

Current mammo extractor checks for either 'for processing' or 'for presentation' images, so rejects these projection objects.

Modify to check all these objects without allowing other SC objects.

[Ed McDonagh]

Turned test for mammo round. Added clause to find SC images with modality MG and image type original. Doesn't work yet as there is no anatomical region code in the header and the get or make cid code is tripping up. Refs #86.

→ <<cset 0f0db7f8351d>>

[Ed McDonagh]

Possible fix for #86 - checks if codevalue is good before trying to get or create. Need to verify it still works where codevalue does exist. Refs #86.

→ <<cset 953f6bee8592>>

[Ed McDonagh]

Make CID code tested and confirmed ok. Both standard and DBT projection images now import. Fixes #86.

→ <<cset a7b319baa126>>