controlButtonStyle 'text' option

This makes the "plain buttons" an alternative to the "video" style playback controls we have been using. Desired by InquirySpace.

IS [#53976313]
Update sensor model type w/controlButtonStyle

IS [#53976313]
Update IS interactives w/text control buttons

IS [#53976313]
Quickly remove "variables" column for demo
Merge branch 'inquiry-space'

Conflicts:
	src/lab/common/controllers/playback-controller.js
keep non-serializable opts out of converted model