"begin_session" metrics are recorded during logout action

[devincowan]

Description of the bug
hs_tracking records login, logout, and begin_session variables in the db (which are later exported for metrics).
In local testing, it appears that the begin_session is recorded during the logout event.

Steps to reproduce the bug:

1. Add a breakpoint at session.record('begin_session', msg)
2. Login, see that the breakpoint is not tripped
3. Logout, see that the breakpoint is tripped

Alternative:

1. Python shell

from hs_tracking.models import Variable
Variable.objects.filter(name="begin_session").last().get_value()

2. Repeat the above before/after login and logout and witness that the "begin_session" variable is created after logout rather than after login.

Expected behavior
begin_session should be recorded at the beginning of a session.

Additional information
HS v2.13.9
Here is our SessionManager class:
https://github.com/hydroshare/hydroshare/blob/2.13.9/hs_tracking/models.py#L25-L67