Introduce namespaces for GET, SET dynalink operations

Introduce namespaces for GET and SET operations. Consequently, standard operations GET_PROPERTY, GET_ELEMENT, GET_METHOD, SET_PROPERTY, and SET_ELEMENT can be replaced with only two operations, GET and SET, and standard namespaces PROPERTY, ELEMENT, and METHOD. The class CompositeOperation that allowed composing multiple operations can be removed and replaced with NamespaceOperation that allows composing one operation with one or more namespaces.