[refine] dwell time ISO 22493:2014(en) definition
Revisit dwell_time.yaml definition with respect to https://www.iso.org/obp/ui/#iso:std:iso:22493:ed-2:v1:en (4 Terms and definitions used in SEM instrumentation)
Revisit dwell_time.yaml definition with respect to https://www.iso.org/obp/ui/#iso:std:iso:22493:ed-2:v1:en (4 Terms and definitions used in SEM instrumentation)