Remove obsolete JFR logger code

The obsolete JFR logger was removed from the build in JDK 9, since it depended on the old com.oracle.jrockit.jfr API that was removed in JDK 9.

We should remove the obsolete source files in modules/javafx.base/src/main/java-jfr and also any references to it, for example: the commented out reference in build.gradle, the references in the NetBeans and IntelliJ IDE files (the Eclipse IDE files also reference it, but they will be taken care of as part of JDK-8196130).