move Runtime{State,Lchan} from pySim.filesystem to new pySim.runtime

Those two are really separate concepts, so let's keep them in separate
source code files.

Change-Id: I9ec54304dd8f4a4cba9487054a8eb8d265c2d340

pySim/apdu/__init__.py

@@ -35,7 +35,7 @@ from construct import *
 from construct import Optional as COptional
 from pySim.construct import *
 from pySim.utils import *
-from pySim.filesystem import RuntimeLchan, RuntimeState, lchan_nr_from_cla
+from pySim.runtime import RuntimeLchan, RuntimeState, lchan_nr_from_cla
 from pySim.filesystem import CardADF, CardFile, TransparentEF, LinFixedEF
 
 """There are multiple levels of decode:

pySim/apdu/ts_102_221.py

@@ -20,6 +20,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 import logging
 from pySim.construct import *
 from pySim.filesystem import *
+from pySim.runtime import RuntimeLchan
 from pySim.apdu import ApduCommand, ApduCommandSet
 from typing import Optional, Dict, Tuple