Add support for registering a custom URLStreamHandler

Because `URL.setURLStreamHandlerFactory(x)` can called only once this method can't use from an application inside of an application server.

Also the service loading via `com.inet.lib.io.URLProtocolManagerURLStreamHandlerProvider` does not work because the application is not on the root classpath.

There already different proprietary solution in different application servers for registering a custom `URLStreamHandler`.

There should be a standard solution.

It can be a method ServletContext like:
```
public void addURLStreamHandler( String protocol, URLStreamHandler handler )
```
or
```
public void addURLStreamHandlerFactory( URLStreamHandlerFactory factory )
```

There can be also an entry in the `web.xml` to register it declarative.

https://github.com/eclipse-ee4j/servlet-api/issues/432

[AB#73](https://dev.azure.com/jakarta-ee-azdo/7cf9a9d3-9854-41e0-9a66-99506a9ed874/_workitems/edit/73)

Start with the linked Servlet API issue #432 and review the proposed ServletContext and web.xml registration approaches described here. Done means the project has agreed on and specified a standard way to register custom URLStreamHandlers for application-server deployments.

Written by the indexing model from the issue text.