feat(router): customize health-check route and add SSL redirect

I pulled #2781 and #2782 into the same PR so they'd be easier to test. This also enabled me to refactor the default route for both the healthcheck endpoint and SSL redirect into the same config block, cleaning up the config and ensuring they apply to everything (i.e. before the controller, builder, store-gateway, or app routes are processed). 

TESTING: add an SSL cert, enable SSL redirects, change the custom health-check endpoint, and ensure nothing is broken
@johanneswuerbach You're right about that. I reverted the commit that moved the redirect from where @mattapperson had it. However, it also doesn't work for me in the original spot, either. Any ideas, @mattapperson?