Update Troubleshooting Guide/Diagnostic Tools NMT categories for JDK18

In JDK18 a new NMT category has been added. This needs to be reflected in the documentation in JDK 18 and JDK 19.

In the table "Table 2-1 Native Memory Tracking Memory Categories" at
https://docs.oracle.com/en/java/javase/18/troubleshoot/diagnostic-tools.html#GUID-5EF7BB07-C903-4EBD-A9C2-EC0E44048D37 the following additions should be done (same for JDK 19 docs):

The row

GC Data use by the GC, such as card table

should be replaced by two rows:

GC | Data use by the GC, such as card table, except the remembered sets

GCCardSet | Data use by the GC's remembered sets (optional, G1 only)