We destroy the log console before the final flush, take that into
account => disable handle message for the ConsoleLogSinkDispatcher if
the corresponding LogConsole was destroyed.

This is a quick and dirty solution, but I don't know any other way for
now!

Because we create a shared_ptr, and because the MainWindow will delete
the widget on exit, we have a double free error...

MISC: Get ride of VivyCli and everything is placed in VivyApplication (because of the way to get the log sink)

- The message no longer outlives the logger
- Update the objects that use the LOG API
- Print more things with the stderr dispatcher
- The UI, src/Lib, src/Lib/Ass, src/Lib/Document use the new LOG API

LOG: Add some logs, pb on flush on exit because the messages outlive the logger (string_view problem)

And some macros to get the current VivyDocument or current
ScriptDocument

MISC: Place all the vivy application in its own namespace, use sub-namespaces for the Ass and Utils parts

Removing icon for the moment

CMP0100 is set to NEW, so moc and uic can be run on .hh files if needed.
This is the new behaviour of the policy so it's safe. It also permits to
separate clearly C++ headers from C ones.

APPLICATION: Add an application object that will be in charge of everything, also use it to store some extra data like icons and such