This refactors all handling of audio-only and last N to 2 features in preparation
for "low bandwidth mode".

The main motivation to do this is that lastN is a "global" setting so it helps
to have all processing for it in a single place.

i18next.options are initialized before interfaceConfig overwrites are processed which leads to wrong translations.

When a participant is pinned in the UI we then proceed to mark it as selected on
the JVB. This will make the participant part of the last N set and will receive
the highest (or configured highest) video quality.

Pinning a participant at the JVB level just makes sure it will be part of the
last N set.

Since only one participant can be pinned in the UI, there is no point in pinning
it at the JVB level, since selecting it already achieved the same result.

Moves getCurrentConferenceUrl method to base/connection to allow reuse.
The new location is not ideal, but looks the best based on the imports
required (trying to avoid circular dependencies).

It was added for
3ea2f00578
over 2 years ago. That's long enough!

* Removes unused translations.

* Fixes using translated strings.

* Moves using latest i18next versions and stop using compatibility modes.

* Sorts i18next options.

* Fixes defaultNS used by i18next.

This is used when translating html tags with data-i18n keys as attributes, used by jQuery-Impromptu.

* ref(user-interaction): remove storing of listener

* ref(user-interaction): move browser requirement check to lib-jitsi-meet

* ref(user-interaction): no inner function for listener, use module scope

This only shows up if we cannot prompt again, like when turning permissions off
in the Settings app in iOS.

The confID is domain.com/RoomName or domain.com/tenant/RoomName, adds the tenant if any and also keeps the room name case.

* fix(invite): decode the meeting name

* squash: try to make mobile join same encoded meeting name as web

* Decodes and generated texts for share and copy meeting info.

Decodes in all cases except when it contains a space, as it will generate wrong links when pasted/shared in external applications.

* fix(conference): require user interaction to unmute in iframe

* squash: explicitly whitelist react native

Brings back the button for generating meeting URLs for calendar events.

Otherwise the participant will not have been added yet
to state so the participant name will not display in
the notification.

When native SDK users end a meeting the view gets disposed and detached from
React, and then the entire app gets destroyed and these errors get printed at
the error level, throwing some people off.

This was hit on a corner case when ConnectionService will deny
the request to start the call. I am not sure, but it could have been
that the conference object has been disposed or closed or something
else, but the fact is that 'conference.room' was not defined and things
crashed. It is not safe to access conference's private field 'room'. It
is true JitsiConference doesn't follow the practice of marking this
field as private with the underscore '_', but it is not a public field.

* Configurable (sub)optimal and unsupported browsers

* maybe this helps somehow

Also, use the helper function to get the display name for a participant.