[cors] Use JDK'S URI class for origin parsing

[Playacem]

As suggested by @zugazagoitia in #2104, we should consider rewriting the custom host scheme port logic in the CORS plugin to use the JDK's URI class.

I plan to look into this next weekend.

Yes, it is. An IPv6 or a domain name (any string of characters) are valid origins.

The Origin header contains a scheme, host and optionally a port. The host, defined by the URI spec is not limited to TLDs, localhost or any internal DNS names are also valid, as well as IP literals.

[Alberto Zugazagoitia]

I'm not sure how we can match using the URI class, it'll end up relying upon some manual parsing or regular expression, but we can use the URI class to normalize/validate non-wildcard URIs since they have already implemented the standard for us.