…eature/11818_Improve_order_of_loading_IDFs_for_nxs_files

 1. IDS mangling used for checksum is now inst name + sha1 of xml
 1.1. sha1 is computed after converitng to linux line endings and trim
 1. VTP file names changes to be same filename as IDS mangling
 1. VTP save directory moved to appdata/mantidproject/instrument/geometryCache
 1. VTP file saving simplified as files based on a checksum cannot be out of date
 1. unit tests updated to account for this
 1. unused methods removed from IDFObject
 1. InstrumentDefinitionParser changed to initialise during constructor
 1. XML parsing changed to lazy load rather than during initialisation.

Still to do:
 1. cache SHA1 checksum if needed
 1. Change the filename reported for nexus files
 1. Manually test
 1. Stop saving the filename to nexus files
 1. update documentation

re #11818

 1. Change the filename reported for nexus files if xml contained within
 1. Stop saving the filename to nexus processed files
 1. removed some unused includes

Still to do:
 1. cache SHA1 checksum if needed
 1. Manually test
 1. update documentation
 1. investigate this error:

ctest -C Debug -J 4 -R LoadEventNexusTest -V

 548: LoadParameterFile-[Error] Bad path syntax: C:\Mantid\Code\Mantid\instrument
\C:\Users\rrc79113\AppData\Roaming\mantidproject\mantid\instrument\HYSPECA_Param
eters.xml. Unable to parse File: in C:/Mantid/Code/Mantid/instrument//C:\Users\r
rc79113\AppData\Roaming\mantidproject\mantid\instrument\HYSPECA_Parameters.xml
548: LoadIDFFromNexus-[Notice] Instrument parameter file: C:\Users\rrc79113\AppD
ata\Roaming\mantidproject\mantid\instrument\HYSPECA_Parameters.xml not found or
un-parsable. Instrument parameter file: C:/Mantid/Code/Mantid/instrument/HYSPECA
_Parameters.xml has been loaded

re #11818

        712 - AlgorithmsTest_CreateDummyCalFileTest (Failed)
        1181 - MDAlgorithmsTest_LoadMDTest (Timeout)
        1195 - MDAlgorithmsTest_MergeMDFilesTest (Failed)

re #11818

re #11818

…/11818_Improve_order_of_loading_IDFs_for_nxs_files

Refs #12656

The instrument_source attribute was removed and so the code hit an
error when trying to load the parameter map. As the instrument_source
is no longer used anywhere there is no point in trying to load it from
older files.
Refs #12656

…s_for_nxs_files

Preserves the expected path within the Nexus file
Refs #12656

Refs #12656