The component Portal is used to teleport the content
in its slot as a child of an element
somewhere else in the DOM, usually 'body'
It is designed to be transparent and is just here to do the teleportation task
OwlEvents (with method `Component.trigger`) are redirected from
any Component instanciated within the Portal (and therefore teleported
somewhere else) to the place it would have been without teleportation
i.e. they are re-triggered onto the Portal root node
Co-authored-by: Aaron Bohy <aab@odoo.com>
closes#184closes#466
Géry Debongnie