Workaround for Derby's limited support for JDBC 4.1 getObject(index, requiredType)

Issue: SPR-12157
Polishing
Make SocketUtils a concrete class

Per the Javadoc for the SocketUtils() constructor, SocketUtils can be
instantiated as a Spring Bean in XML configuration files; however,
SocketUtils is currently abstract which prevents such usage.

This commit removes the 'abstract' declaration thereby allowing
SocketUtils to be instantiated as a Spring bean.

Issue: SPR-12169
Consistent support for java.util.Optional for all applicable handler method arguments

Issue: SPR-12171
Polishing