arti-hyper crate is obsolete with hyper 1 and should probably be removed or something

arti-hyper contains glue to connect arti-client and hyper. But, hyper 0.x. hyper 1 is better and doesn't need this glue.

In !1845 (merged), @ramidzkh provided fresh examples in examples/hyper/ which don't use arti-hyper and don't contain much boilerplate.

So the crate arti-hyper is obsolete, and its examples are no longer good examples to follow. We should do something about this. I think we should:

1. Replace the arti-hyper crate with a tombstone crate explaining this situation and referring to the new examples from !1845 (merged)
2. Release the tombstone once and then cease publishing it.
3. Eventually, delete it from git.