Button/event to 'open new tab in speaker view, with follow-active'

[mirisuzanne]

There could be an even higher level button/even 'start presenting' which would:

• reset to the first slide
• turn on key-control and follow-active
• switch to presentation mode
• open a new tab, with key-control and follow active, in speaker mode

See the request from Elly Loel on Mastodon.