Fix Java 17 compilation and test issues (#12353)

* Adds --add-opens to the surefire-maven-plugin config required for deserialization using Gson/XStream
* Upgrades plugin dependencies to JDK 17 compatible versions
* Replaces some reflection that no longer works on JDK 17
* Fixes issues when mocking Random
* Run Nashorn dependant tests only on JDK < 15

Signed-off-by: Wouter Born <github@maindrain.net>

pom.xml

@@ -385,6 +385,10 @@ Import-Package: \\
           <artifactId>maven-surefire-plugin</artifactId>
           <version>3.0.0-M5</version>
           <configuration>
+            <argLine>
+              --add-opens java.base/java.lang=ALL-UNNAMED
+              --add-opens java.base/java.util=ALL-UNNAMED
+            </argLine>
             <systemPropertyVariables>
               <junit.jupiter.execution.timeout.default>15 m</junit.jupiter.execution.timeout.default>
             </systemPropertyVariables>