Ensure the view extension only runs one time every frame in the editor

[pramberg]

Description

When using the material editor in a separate window, so both the level editor and the material editor viewports are visible, the view extension is run twice. This causes the colors to behave sporadically. The optimal solution would probably be to use the viewport/window the use last interacted with, but I'm unsure if that's possible. Regardless, this needs to be fixed in some way, because it makes testing more difficult than it has to be.

Requirements

• [x] The view extension is only run for one view each frame

[pramberg]

This was fixed in 814f3494487bb4576bffe9d32a1fedcac7b260f3. The view extension only executes for the last used viewport