fix(console): the console daemons hold to what the console page allowed

The token now names the console type it was made for: novncd accepts only
a VNC page's token and socketiod only a serial page's, so a VNC page's
token no longer opens the serial console without the VNC password.

A VNC session re-checks every 10 s, as the serial one did, that its user
may still open the console; a deactivated user or a removed owner loses
it. The check (may_still_open) moves to console.tokens for both daemons.

conf/daemon/consolecallback

@@ -20,16 +20,13 @@ os.environ.setdefault("DJANGO_SETTINGS_MODULE", "webvirtcloud.settings")
 django.setup()
 
 import libvirt  # noqa: E402
-from django import db  # noqa: E402
-from django.contrib.auth import get_user_model  # noqa: E402
 
 from instances.models import Instance  # noqa: E402
-from instances.utils import can_open_console  # noqa: E402
+from console.tokens import ACCESS_CHECK, may_still_open  # noqa: E402
 from operations.utils import public_error_text  # noqa: E402
 from vrtManager.connection import connection_manager  # noqa: E402
 
 SEND_WAIT = 5  # seconds a paste may wait for the VM to take it
-ACCESS_CHECK = 10  # seconds between checks that the user may still use the console
 
 
 log = logging.getLogger("consolecallback")
@@ -112,16 +109,6 @@ def from_vm(stream, events, console):
     os.write(1, data)
 
 
-def may_still_open(user_id, instance):
-    """The user still may open the console: an owner may have been removed or
-    the user deactivated since the session started."""
-    try:
-        user = get_user_model().objects.filter(pk=user_id).first()
-        return user is not None and can_open_console(user, instance)
-    finally:
-        db.connection.close()  # a session may last for days: no idle connection meanwhile
-
-
 def main():
     # what the operator reads goes to socketiod's log (the journal, docker
     # logs), on the descriptor it names; the user's terminal gets a short line