Prevent mag warning from showing in 3D viewport

[hotzenklotz]

The PR fix a small isse whereby a toast warning would show up every time one opened the 3D viewport fullscreen. The message is about not having apprirate data for the loaded mag and does not really make sense when the 3D viewport is in fullscreen mode.

This PR prevents this message from showing when maximizing the 3D viewport.

URL of deployed dev instance (used for testing):

• https://___.webknossos.xyz

Steps to test:

• Maximize 3D viewport
• Oberserve no more message popping up

Issues:

• fixes Maximizing 3D viewport triggers mag warning #6354

---

(Please delete unneeded items, merge only when none are left open)

• Updated (unreleased) changelog
• Updated (unreleased) migration guide if applicable
• Updated documentation if applicable
• Adapted wk-connect if datastore API changes
• Adapted wk-libs python client if relevant API parts change
• Needs datastore update after deployment
• Ready for review

[philippotto]

the activeViewport is the one that the mouse hovers currently (or most recently). it's not necessarily in fullscreen then. this means that the toast would likely disappear and re-appear when moving the mouse to the 3d viewport and out of it again.
to get the fullscreen info, I'd do something like the following:

const extent_xy = getViewportExtents(state)["PLANE_XY"];
const extent_yz = getViewportExtents(state)["PLANE_YZ"];
...
const areas = [extent_xy, extent_yz, ...].map(([width, height]) => width * height);
const areDataviewportsInvisible = _.sum(areas) == 0;

could be a helper function next to getViewportExtents in view_mode_accessors.

[hotzenklotz]

@philippotto I applied your suggestion, please have a look again.

[philippotto]

excellent, works well 👍