Deprecate (and mark for removal) ExtendedHttpService

The ExtendedHttpService is effectively unused in platform and
uses the abandoned HttpService it is API.

We therefore should deprecate and remove that to get rid of the
dependency here a more modern replacement for the purpose of this
extended form (registering filters) is today the [Http Whiteboard
Specification](https://docs.osgi.org/specification/osgi.cmpn/7.0.0/service.http.whiteboard.html)

Author: laeubi

bundles/org.eclipse.equinox.http.servlet/src/org/eclipse/equinox/http/servlet/ExtendedHttpService.java

@@ -25,6 +25,7 @@
  * @noimplement This interface is not intended to be implemented by clients.
  */
 @ProviderType
+@Deprecated(forRemoval = true)
 public interface ExtendedHttpService extends HttpService {
 
 	/**

bundles/org.eclipse.equinox.http.servlet/src/org/eclipse/equinox/http/servlet/HttpServiceMultipartServlet.java

@@ -20,6 +20,7 @@
  * @deprecated No longer required.
  * @since 1.3
  */
+@Deprecated(forRemoval = true)
 public class HttpServiceMultipartServlet extends HttpServlet {
 	private static final long serialVersionUID = 2281118780429323631L;
 }