Default generated .gitmodules submodule nametags

[Mangonels]

In order to prevent issues when making a clean/templated setup from roguelite, and since each submodule's nametag isn't used or referenced from anywhere else in the whole roguelite environment, I think it would be best if these submodule nametags were same as if newly generated.

In essence I just changed the submodules names in .gitmodules.

This affects the godot-cpp and godot-engine submodules, which are the only ones without a default nametag in .gitmodules.