Moded time slice to Python algo, added docs

Refs #10264
Added new algorithm to GUI

Refs #10264
Use a data selctor for calibration file

Refs #10264
Added grouped output, usage example and unit test

Refs #10264
Fix numpy issues for TimeSlice

Refs #10264
Allow single spectra in diagnostics

Refs #10264
Merge remote-tracking branch 'origin/feature/10264_indirect_slice_algorithm'