Make Stop dialog clearer: people keep initiating stitching

[raacampbell]

There should be multiple buttons so it's more explicit what choice to make. Get rid of the checkbox. It should have two choices made one after the other

First there are three buttons:

1. "Stop and initiate stitching: I'm done"
2. "Stop but do not initiate stitching: I want to get more data from this sample."
3. "Cancel"

Then the buttons change:

1. "Turn off laser after stop"
2. "Leave laser on after stop"
3. "Cancel stop"

#352