Bounding box queries can use private coordinates #68

[pleary]

• Refactors how query filters are applied for collection project trusting
• Core logic about trusting is extracted, and can be applied to place filters and also bounding box filters, which resolves bounding box queries don't use private coordinates, even for obs you have permission to see #68

[kueda]

This looks good and addresses the issue raised in #68, so I don't think there are any blocking problems. That said, I would like to see some integration tests showing that this is working, something along the lines of

describe( "filtering by bounding box", ( ) => {
  describe( "including an obscured observation's true coordinates but not the obscured coordinates", ( ) => {
    it( "should return the observation when viewed by the observer" );
    it( "should return the observation when viewed someone the observer trusts" );
    it( "should not return the observation when viewed by someone the observer doesn't trust" );
  } );
  describe( "including an obscured observation's obscured coordinates but not the true coordinates", ( ) => {
    it( "should not return the observation when viewed by the observer" );
    it( "should not return the observation when viewed someone the observer trusts" );
    it( "should return the observation when viewed by someone the observer doesn't trust" );
  } );
} );