* Add SECP256k1/ECDSA support for transaction signing.

* Refactoring and fixes

* Fix for contracts

* Avoid breaking runtime host function

* Build fixes, make subkey work more generaically.

* Fix tests

* Dedpulicate a bit of code, remove unneeded code, docs

* Bump runtime version

* Fix a test and clean up some code.

* Derivation can derive seed.

* Whitespace

* Bump runtime again.

* Update core/primitives/src/crypto.rs

Co-Authored-By: Kian Paimani <[email protected]>

* Update core/primitives/src/ecdsa.rs

Co-Authored-By: Kian Paimani <[email protected]>

* Fix AppVerify