Rework JavaScript support to GraalVM

[artembilan]

See more info in GraalVM: https://www.graalvm.org/reference-manual/js/JavaInteroperability/.

It may turn out just to a simple GraalVmJavaScriptExecutor implementation since making it working we need to expose these variables:

<script:variable name="polyglot.js.allowHostAccess" value="#{true}"/>
<script:variable name="polyglot.js.allowHostClassLookup" value="#{true}"/>

For now JavaScript tests are disable if no GraalVM in classpath.