substrate-primitves upstream PR with feature "with_crypto"

[brenzi]

Our port would be more maintainable if added upstream.
parity might accept a new feature enable_native_crypto that allows to have a no_std build which provides all the crypto primitives we need.

[brenzi]

do the same with application-crypto forked to:
https://github.com/scs/substraTEE-worker/tree/brenzi-upstream-sync/application-crypto

[brenzi]

started work on this:

https://github.com/scs/substrate/tree/brenzi-no-std-crypto

decided to chose a more recent upstream commit to start from. So, to test this, I'm upgrading substratee too:

https://github.com/scs/substraTEE-node/tree/brenzi-substrate-fork

https://github.com/scs/substraTEE-worker/tree/brenzi-substrate-fork

not yet working

[brenzi]

Here's our PR:
paritytech/substrate#3778

[brenzi]

see #42