Improve dragging tab to a new window on wayland (support for xdg-toplevel-drag)

[Friedrich]

Currently on Linux systems with wayland the user experience when dragging a tab to open a new window is not good. The window only spawns once the user drops the tab and the new window spawns in the wrong location.

From my understanding the xdg-toplevel-drag protocol can be used to solve this issue.

[Jon]

Thanks for submitting an idea to the Mozilla Connect community! Your idea is now open to votes (aka kudos) and comments.

[mknn]

Dragging out is crucial, experience on wayland forces me to switch to another browser. It is terrible on windows comparing to other browsers, but on wayland is really tragic.

[7rst1]

This deserves more kudos. For me, Firefox doesn't even split out a new window half of the time, and the tabs falls back in its original window.

My guess is that thousands of Firefox users on Linux have this issue and is somewhat frustrated by it, and that it falls in the weird valley of being just minute enough for people to not bother searching it up. Fixing this would be a major QoL update for Linux users.