sapp: Remove sapp-* crates

First miniquad version used to depend on sokol_app.h
C and ObjectiveC code required different build tools, so miniquad
used to have lots of different [build-depdendencies] for varios platforms.

Back then(and probably still) cargo did not had per-platform build-dependencies.
So it was a natural solution to put a native code into a sub-crates. Each could
have its own build-dependencies and do not interference with other platforms.

But lately, one by one, sapp-* got rewrited in rust.

And having them as separate crates became a huge pain point - its 8 crates, each
with its own versions. To fix a little bug requires a version bump, etc, etc.

We do not have any [build-dependencies] anymore at all. And no C/ObjC code as
well.

Version bump

Allow icon to be cloned

Version bump

version bump

Bump version again

Bump version

Bump version

Version bump

Somehow last "Version bump" commit got lost, so its quite a bit bump :/

Version bump