Sim specific PhET-iO wrappers not being copied during build

[samreid]

Discovered in https://github.com/phetsims/phet-io-wrapper-sonification/issues/84. It seems the ability to build a sim-specific PhET-iO wrapper was dropped, probably circa 34923a2 (part of #680) or thereabouts.

[samreid]

Proposed fixes pushed, it seemed straightforward. @zepumph can you please review?

[KatieWoe]

CT seems to be showing errors. @zepumph mentioned it may be related to this issue.

[zepumph]

The changes look good. Thanks @samreid. Review from here:

• const simSpecificWrappers = packageObject.phet && packageObject.phet[ 'phet-io' ] && packageObject.phet[ 'phet-io' ].wrappers ? packageObject.phet[ 'phet-io' ].wrappers : [];

  Instead you could use _.at(packageObject, "phet['phet-io'].wrappers") which will return [undefined] if it doesn't exist. Just a thought, no strong preference.

• there are still dedicated wrappers in chipper/data/wrappers. They should be removed and the same process done to them. I made a commit to review.

[samreid]

I considered

// A
_.at( packageObject, "phet[ 'phet-io' ].wrappers" );// eslint-disable-line 

// B
_.at( packageObject, 'phet[\'phet-io\'].wrappers' );

// C
_.at( packageObject, 'phet["phet-io"].wrappers' );

I prefer the former because searches for phet[ 'phet-io' ] won't be missed. However, I realized that we would need to guard on undefined to prevent processing that. Maybe simpler to improve formatting of the prior strategy?

[samreid]

Also, I reviewed the changes that moved classroom activity, lab book and arithmetic wrappers out. Tested building and running arithmetic's wrapper. Looks great, closing.

[zepumph]

No need to reopen if you still like your way more, I just wanted to post what the difference would be. I think I prefer the latter, but likely only because _.at is new and fancy to me.

  // Add sim-specific wrappers
  const simSpecificWrappers = packageObject.phet &&
                              packageObject.phet[ 'phet-io' ] &&
                              packageObject.phet[ 'phet-io' ].wrappers ?
                              packageObject.phet[ 'phet-io' ].wrappers : [];

// vs

  const simSpecificWrappers = _.at( packageObject, 'phet[ "phet-io" ].wrappers' )[ 0 ] ?
                              _.at( packageObject, 'phet[ "phet-io" ].wrappers' )[ 0 ] : [];

[samreid]

It's a good use of _.at and much more concise, but my concern is that it impedes text-searchability of the term phet[ 'phet-io' ].