Provide security matchers for actuator links

Fixes gh-12353

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/PathMappedEndpoints.java

@@ -75,6 +75,14 @@ public class PathMappedEndpoints implements Iterable<PathMappedEndpoint> {
 		return Collections.unmodifiableMap(endpoints);
 	}
 
+	/**
+	 * Return the base path for the endpoints.
+	 * @return the base path
+	 */
+	public String getBasePath() {
+		return this.basePath;
+	}
+
 	/**
 	 * Return the root path for the endpoint with the given ID or {@code null} if the
 	 * endpoint cannot be found.