change datatype property to datainfo

- according to SECoP v1.0
- internally the name 'datatype' is kept

Change-Id: I0298a45f2db529ced3a07e2e9b344c91cfb7bb88
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/21300
Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

secop/client/baseclient.py

@@ -386,7 +386,7 @@ class Client(object):
 
             for module, moduleData in self.describing_data['modules'].items():
                 for aname, adata in moduleData['accessibles'].items():
-                    datatype = get_datatype(adata['datatype'])
+                    datatype = get_datatype(adata.pop('datainfo'))
                     # *sigh* special handling for 'some' parameters....
                     if isinstance(datatype, EnumType):
                         datatype._enum.name = aname