ForwardingJavaPlatform is causing trouble

As discovered in https://github.com/apache/netbeans/pull/6213#discussion_r1359320621, the proxy class delegates a subset of the methods to the wrapped `JavaPlatform` which creates a frankenstein platform.

https://github.com/apache/netbeans/blob/a9aeefafc04e2d79a4702be88d890324365989bd/java/java.platform/src/org/netbeans/spi/java/platform/support/ForwardingJavaPlatform.java#L36

https://github.com/apache/netbeans/blob/a9aeefafc04e2d79a4702be88d890324365989bd/java/java.platform/src/org/netbeans/api/java/platform/JavaPlatform.java#L41
has final methods and was not designed to be extended / delegated in that way.

It is possible that it was actually the intention of that class to leave some capabilities out, however it is passed to places which expect a working `JavaPlatform` object, with non-empty properties etc.

Lets try to figure out what `ForwardingJavaPlatform` was supposed to achieve (hide the event system?) and then fix it if possible.

Read java/java.platform/src/org/netbeans/spi/java/platform/support/ForwardingJavaPlatform.java and the linked JavaPlatform.java definition, then review the discussion in PR #6213. Determine whether the proxy is intended to hide the event system or omit capabilities; done means resolving that behavior so callers receive a working JavaPlatform with the expected properties and capabilities.

Written by the indexing model from the issue text.