Drop uimaj-adapter-soap due to Java 16 issues in Eclipse

uimaj-adapter-soap does not build in Eclipse against Java 16.

When changing the Java source/target level in Maven Build from 1.8 to 16, the uimaj-adapter-soap displays errors: "QName cannot be resolved to a type".

The reason for this is that the module has multiple dependencies including the JDK itself which provides this class and in Java Modules, a package must be exclusive to a certain module.

In particular, the module depends on Apache Axis JAX-RPC which contains javax.xml.namespace.QName.

I wonder if the SOAP module is actually still used by anybody - I'd personally tend towards dropping it.