Properly handle failure when creating a space from resources

[JammingBen]

This is a follow-up for #8730.

What should happen when something fails during the copy-process of resources to a new space? Should we revert the whole process (= delete the newly created space again)? Or should we keep the space despite its missing items?

Either way, we need to adjust the error message in such case. Currently it would state Creating space failed….

[AlexAndBear]

@tbsbdr could you please make a decision. I am fine with deleting the space as "the mission failed".
I don't expect the user comparing the space content and copy the missing files by hand.

If so, could you also provide a dedicated message string ? 🖤