Update gdnative to 0.10.0

[derivator]

Hadn't seen that you had already done most of this work here when I started this... Not sending this PR to step on your toes, but since that branch is kinda old and has merge conflicts maybe this can help someone...

[setzer22]

Hi! And thanks for the PR 😄

As you already mentioned, this work was already started in #30 when @Bromeon took care of updating the branch to use godot-rust 0.10.0.rc-1 which is almost the same as the recently released 0.10.0.

The current roadblock is merging the new code onto the main branch. The two branches have diverged a bit now, and on top of that I would also like to move it to the recently released egui 0.17. I will try to find time for this soon, but I'm glad you were able to make it work on your end! 👍

[derivator]

I would also like to move it to the recently released egui 0.17

Looking forward to it 👍 I had a quick look at doing this update also, but that requires updating egui-theme, which is one dependency layer deeper than I want to take on right now 😅

[jacobsky]

I have the bulk of these changes resolved with #33 so I think we can go ahead and close this PR for now. Thank you for the help @derivator , if you want you can take a look at and test the changes on that branch and it would help give some confidence to the changes :)