Widgets should be visible and pinned by default

[ara4n]

Otherwise they're impossible to discover.

[hazzuk]

This would still be helpful, currently I provide a guide for my end users in the room chat of the widget, explaining how to pin and maximise it.

This issue is also related to #15737, which suggests 'widgets pinned by default' and 'adding a toolbar icon for the widget when pinned'. But a very good point was raised, "We could instead allow widgets to be displayed as individual rooms", which could be the ideal outcome.