Merge branch 'master' into feature/10470_grouped_dets_sxdnorm

Conflicts:
	Code/Mantid/Framework/MDAlgorithms/src/MDNormSXD.cpp
Refs #10470
Fix bug for 1:1 detector mapping.

ExperimentInfo throws if no mappings are defined.
Refs #10470
Merge branch 'feature/10470_grouped_dets_sxdnorm' into develop