collapse --sample and --sample-window into just --sample

[QMalcolm]

During the alpha implementation of sample mode we added CLI flags/options

1. --sample for turning sample mode on/off
2. --sample-window for specifying the window for sample mode

During the feedback session and additional discussion, we found it is likely better to have only one sample mode flag/option. With that in mind, we are going to combine the two into one. Thus, --sample will now take the sample window specification and --sample-window will go away.