Added preview plot for slice, need to fix range selectors

Refs #10299
Update preview plot on range selectors

Refs #10299
Only change required XML

Refs #10299
Only replot when new filename has been entered

Refs #10299
Fix background range issue

Refs #10299
Merge branch 'master' into feature/10299_indirect_slice_preview_plot

Conflicts:
	Code/Mantid/MantidQt/CustomInterfaces/src/IndirectDiagnostics.cpp

Refs #10299
Protect against WS naming conflicts

Can happen when algorithm exectutes immediately fater it has finished

Refs #10299
Merge branch 'feature/10299_indirect_slice_preview_plot' into develop