Issue673 Empty NumericValues and workaround for Azurion AcquisitionDeviceType

Temporary local fix for empty calibration factor for ref #673. However, structure of RDSR is different so accumulated data isn't being extracted. Need to walk through the RDSR and the code to establish what is going on!

Hacky fix for non-conformant Philips Azurion to get accumulated fluoro data. Refs #673

Made the numeric value test more generic. Tests still pass. Refs #673

PyCharm code reformat due to extra long lines from last commit. Refs #673

PyCharm imports optimised. Refs #673

Forgot to remove test_numeric_import from _calibration. Refs #673

Used the same hacky method to define as RF as was used to trigger accumulated fluoro fields. Refs #673

Added ref #673 to changes and updated release notes.