Create own resume dialog, which acts the same way as a floating
window. Thus it does not disturb the user more than any
other VLC panel and consequently does not block the user in doing
other operations.

This fixes floating behaviour (#13886) any makes it more easy
to implement any other fancy_dialog_whatever we might add later.
Current design is a copy of the currently used alert window.

Also raised the timeout value to 10 secs as users are complaining
6 sec is not long enough.

close #13886

If libvlc_media_player_get_full_chapter_descriptions is called with a
title set to -1, it uses the current title.

vlc_cond_timedwait() returns non-zero when the deadline is reached.

Do not register it if keys are disabled. Do not leave it dangling if
thread creation fails.

No need to duplicate debug from net_Connect()...

p_finder is not visible to other threads at this point.

From the downloader thread, b_close is always true.

vlc_cancel() is not used, so this was a no-op.