Video Subject: VideoContoller missing unit tests, storybook, and Readme documentation

[goplayoutside3]

Package

lib-classifier

Describe the problem and solution

• The features of VideoController are not documented in its Readme file. Similar to other components in lib-classifier, the basic functionality should be described in its Readme.
• VideoController and its components do not have any unit tests. This is an opportunity to add tests with React Testing Library rather than enzyme.
• VideoController and its components do not have any storybook stories.

Additional context

This issue documentation is sorted into the Video Annotator project board. It's part of an effort to improve the video subject viewer code for migrating Woodpecker Cavity Cam to FEM.

[goplayoutside3]

Noting that scrubbing the video controller is not as smooth as PFE. I'll investigate if the UX can be improved.