Log user out from UI on 401

Downgrade to `python-ldap==3.4.3` in `poetry.lock`

Downgrade `python-ldap` from version `3.4.4` to `3.4.3` in `poetry.lock`
because we want `poetry.lock` and `conda-environment.yml` pins in sync
and there is no version `3.4.4` in the *conda* repositories.

<#1515>
<conda-forge/python-ldap-feedstock#27>

Bumped mxcubecore

Replace "Proposal" with "Session" in nav bar

Not returning the traceback on exception

On lost connection, check if we still have a valid session.

Handle the cases, where during loss of connection to the backend,
our session becomes invalid.

If no valid session exist, swith to login page.

Adding documentation and dependency for missing video stream

Don't call `login_info` twice on login/logout

Remove manual reconnect of logging websocket

Show error boundary when server is down