Cast API query parameter string booleans to real booleans

[liammulh]

Some of the API routes expect query parameters to be present. For example, see the function associated with the simNamesAndTitles API route:

rosetta/src/server/translationApi/api/simNamesAndTitles.js

Lines 19 to 22 in b1e931d

	const simNamesAndTitles = async ( req, res ) => {
	logger.info( 'responding with sim names and titles' );
	res.json( getSimNamesAndTitles( await getSimMetadata(), req.query.isTeamMember ) );
	};

The req.query.isTeamMember is returned as a string. We should cast it (and other API query parameter string booleans) to a real boolean so that it doesn't trip anyone up in the future. This will also involve changing the parameters to the functions we call using the API query parameter string booleans.

To do this comprehensively, we should search across the project for instances of req.query.*. We should note where these variables are being used, cast them to booleans in the API callback functions, and modify the functions that use these variable so that they expect booleans rather than string booleans.

[liammulh]

As of a9a31d6, I believe this is done awaiting deploy.

[liammulh]

This is deployed.

[phet-dev]

Reopening because there is a TODO marked for this issue.