Support overlapping catch-all and static routes

[ibraheemdev]

With the backtracking logic added in #2897, I think routes like /*wild and /static can be supported with minimal effort. By simply removing the catch-all route check when inserting a route, adding a wildcard route (/*wild) and then a static route (/static) works as expected, with static routes being given higher priority because of the addChild logic. Adding a static route first and then a wildcard might take a bit more work, but I think it's worth supporting the common use-case of serving static files (ie: a react app) at the root of the app while also having some other static routes.

[artob]

Related issue: #2920