kie-server: clean-up deps
kie-server-client: use KieRemoteHttp[Request|Response] instead of resteasy
kie-server: use own class for list of ServiceResponses

 * this makes it much easier for jaxb/json serialization
   to figure out how to actually transfrom the object
   to string and vice versa.
 * without this change the jaxb and json marshallers
   would need additional configuration, which is not
   idea
kie-server-client: refactoring to promote more code reuse
kie-server-client: centralize error handling
kie-server-client: add few unit tests
kie-server-client: check the result type before returning

 * this should make the client more type-safe as now it
   checks whether the ServiceResponse<T> instance actually
   contains object of type T. If it does not, exception
   is thrown.
 * before these changes users could encounter
   ClassCastException when retrieving the result object
   that is not of the expected type
BZ-1164885: fixing exec server getContainerInfo and getScannerInfo API