Use PathContainer in web.reactive.function.server

This commit uses the newly introduced `PathContainer` and `RequestPath`
support in the functional web framework. It exposes the path container
as property in `ServerRequest`, and uses that in the path-based
`RequestPredicates`.

spring-web/src/main/java/org/springframework/http/server/reactive/RequestPath.java

@@ -15,6 +15,9 @@
  */
 package org.springframework.http.server.reactive;
 
+import java.net.URI;
+import java.nio.charset.Charset;
+
 /**
  * Represents the complete path for a request.
  *
@@ -38,4 +41,11 @@ public interface RequestPath extends PathContainer {
 	 */
 	PathContainer pathWithinApplication();
 
+	/**
+	 * Create a new {@code RequestPath} with the given parameters.
+	 */
+	static RequestPath create(URI uri, String contextPath, Charset charset) {
+		return new DefaultRequestPath(uri, contextPath, charset);
+	}
+
 }

spring-web/src/main/java/org/springframework/web/util/pattern/PathPattern.java

@@ -539,8 +539,8 @@ public class PathPattern implements Comparable<PathPattern> {
 		/**
 		 * Return the part of a path that was not matched by a pattern.
 		 */
-		public String getPathRemaining() {
-			return this.pathRemaining.value();
+		public PathContainer getPathRemaining() {
+			return this.pathRemaining;
 		}
 
 		/**