We have the functions reload and redirect which modify window.location.
Use them and do not directly modify window.location so that we have
fewer places of direct window.location modifications and it is easier to
refactor them.

* M1: device change now uses new flow.  fundamentally "works" but may be corner cases/side effects to other flows. haven't touched ffox yet

* M2: change toggle screenshare flows to use the new video replacement chain

* remove the old 'useVideoStream' and replace it with the new one

* use the new (and renamed back from the shim) 'dispose' method

* tweaks to work with the sdp overhaul changes in lib-jitsi-meet

* change the order in which we call dispose (to handle dispose being reverted back to how it is currently on master)

* move useAudioStream over to new flow

* restore useVideoStream doc

* handle rename JitsiConference::replaceStream -> JitsiConference::replaceTrack

* fix useAudioStream and useVideoStream to return a promise again

Using sessionStorage to save whether user is guest or not.

Also removes device change listener, cause when PC wakeups devices will be reconnected and we can try open the local video again.

Adds some safety checks for disabled contactlist.

It looks weird when the page reload overlay appears and the conference
continues in the background (the connection to the JVB remains active).
The library will not recover and the conference can not continue without
the signalling, so the room should be left and media stopped.

Removing translateString forces using data-i18n attributes, to make sure we do not forget to set them. Missing data-i18n attributes is a problem with late loading where we can end up without translation, without text. Missing data-i18n attributes is also problem that strings will not be translated when changing language.
Fixes a bug in invite dialog, where remove password button was shown for non moderators.