Move soccer context to a common repo

[marlitas]

The fourth screen in Mean: Share and Balance will now have a soccer context as well. This means we need to move out the following pieces to a common repo that can be shared between the two sims.

• SoccerBallNode
• SoccerPlayerNode
• CAVObjectNode
• NumberLineNode?
• CAVPlotNode?
• SoccerBall
• SoccerPlayer
• Pose
• AnimationMode
• ObjectType?

[samreid]

Maybe call it soccer-common? And make sure to preserve history via copy-history-to-different-repo.js

[marlitas]

I went through the model files and added TODO's to try and organize what classes along with their properties that will need to be moved out. I think there's some conversation on the exact strategy we feel would be best to move this forward. Probably good to discuss together first.

[samreid]

@marlitas and I started on creating a soccer-common/ subdirectory so we can get things organized before changing repos. I'm continuing to search for which files are relevant, by checking imports.

[samreid]

After the commits above, there are 3 remaining imports from outside of soccer-common. You can search them using this regex: \'\.\.\/\.\.\/\w

Also, when we move soccer-common to a separate repo, we will incur overhead for committing in 2x repos, type checking 2x repos, linting 2x repos, branching would become more difficult, issues will be managed in 2x repos. The project board will need to know how to work with 2x repos, etc. So I considered we may want to add a lint rule like the regex above and keep working with soccer-common embedded in center-and-variability/ a bit longer.

Also, it seems we should either add (a) a test harness for soccer-common or (b) initial draft of mean-share-and-balance usage, so we can make sure it is suitable for reuse.