Routes added to add_sink override static routes added with add_static_route

Hi Falcon team,

Thanks for all your hard work. I ran into an issue today when I tried to make use of the add_static_route method.

Our project uses add_sink to implement a custom handler for requests with no corresponding handler. However, that add_sink function would gobble up any requests that we intended to be handled by the static route:

api.add_static_route('/static', valid_static_file_path) # Would never get called
api.add_sink(unmatched_route_handler) # Would always swallow calls to assets at `/static/WHATEVER`

The case was the same whether the static route was added before or after the sink.

I would expect that if a static route is added, that resource path is excluded for any sink handlers.

My workaround for now was to basically use a regex on the sink to exclude the static path:

api.add_sink(unmatched_route_auth_wrapper, '^((?!static).)*$')

[CaselIT]

I’ve added a pr #1769 to invert the precedence of the sinks and static routes via a configuration parameter of the app.

By default the behavior is the same as the current one, so no breaking change was added

[CaselIT]

I think how the App interacts with the sinks and static files could be unified to have a single for loop, the two arrays can be simply chained one way or the other according to the setting (this could also be done statically, each time a sink/static file route is added).

https://github.com/falconry/falcon/blob/d946b4f0acf6c9fd25015f517499880c19533932/falcon/app.py#L845-L859