test(grid-list): avoid recompiling all fixtures for each test (#12896)
test(grid-list): avoid recompiling all fixtures for each test (#12896)

Reworks the grid list to avoid having to recompile all the other fixture for each test. This shaves of a few seconds of the test runs. Also does some minor cleanup.
angular/components,josephperrott/material2,DevVersion/material2,mmalerba/material2,jelbourn/material2,Jefiozie/material2,crisbeto/material2,josephperrott/material2,crisbeto/material2,andrewseguin/material2,DevVersion/material2,DevVersion/material2,josephperrott/material2,andrewseguin/material2,Jefiozie/material2,jelbourn/material2,andrewseguin/material2,Jefiozie/material2,josephperrott/material2,crisbeto/material2,DevVersion/material2,josephperrott/material2,angular/components,jelbourn/material2,Jefiozie/material2,mmalerba/material2,angular/components,andrewseguin/material2,jelbourn/material2,mmalerba/material2,mmalerba/material2,andrewseguin/material2,angular/components,mmalerba/material2,crisbeto/material2,jelbourn/material2,Jefiozie/material2,DevVersion/material2