Uses nullish coalescing and optional chaining.

It's an evolution of audio-only mode, where we also allow for receiving a remote
screen-share.

Diving deeper: this basically sets last N to 1 or 0 depending on the
availability of a screen-share.

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.