Token-less login to Github and Kittycad

[pierremtb]

[pierremtb]

Seems like for KittyCAD, the way to go would be something similar to https://github.com/KittyCAD/cli/blob/main/src/cmd_auth.rs#L117

[pierremtb]

Now questioning the value of this. If I don't make the click-to-login perfect, users might get signed off because a refresh token expired or something that's not transparent at all for them. But the token are long-lived by design, and I think the direct links make the experience a good-enough compromise