feat: Allow closing popovers by right clicking the curtain

[jespertheend]

Fixes #442

[jespertheend]

Seems like e2e tests are failing because clicking items in contextmenus isn't working anymore.
The reason being that preventDefault() is preventing the click event from firing.
Normally the this.#activePopovers.some() statement should prevent this, but submenus aren't properly added to the popovermanager. (#515)

[jespertheend]

Another problem seems to be that it's no longer possible to drag assets to the entry point popover in the build view