* ref(Filmstrip): Optimize resizes.

* fix(thumbnails): resize.

* fix(thumbnails): Issue with height 0, width 0.

* doc(Filmstrip): Improve JSDoc.

We are going to implement the invite dialog *inside* the SDK, so there is no
need to have all this machinery anymore.

BaseApp does all the heavy-lifting related to creating the redux store,
navigation, and so on.

App currently handles URL props and actually triggering navigation based on
them.

If multiple JitsiMeetView instances are created (not necessarily
existing at once), it's possible to hit a TypeError when reading the
React Component props of the currently mounted App. Anyway, in certain
places we're already protecting against that out of abundance of caution
so it makes no sense to not protect everywhere.

Hristo Terezov, Chris Cordle, and I/Lyubomir Marinov agreed that we'd
try to use "invite" & "invitee(s)" in Web/React's iframe API,
mobile/react-native's SDK invite API, and internally for the purposes of
consistency, ease of understanding, etc.

This can happen if there are multiple JitsiMeetView instances are active at the
same time, because there is a single bridge, which means all of them would get
the events.