* Add KEY_KIND_ID to the public trait

This change is being introduced for the purpose of identifying a public
key with it's identifier and algorithm "kind".

* Use `sign_with` as implemented in BareCryptoStore

* Implement `sign_with` in sc_keystore

* Fix inconsistencies, use *_KIND_ID in sp_core testing

* Rename KeyKindId to CryptoTypeId

* Remove pair-returning functions from BareCryptoStore trait

* Define CryptoTypeId in app-crypto macros

* Add functions to get keys supported by keystore

* Fix sign_with signature to include CryptoTypePublicPair

* Add `sign_with_any` and `sign_with_all`

* Use keystore.sign_with in auth_discovery

* Rename get_supported_keys -> supported_keys

* Added headers to function docstrings

* Use chain instead of extending a temp vector

* Fixed some code formatting

* Restrict size of CryptoTypeId

This is to be able to use Encode/Decode derives and the overcome having
the size being unknown at compile-time.

* Implement sign_with in the trait itself

* Remove whitespace

* Use key_type also as a CryptoTypeId in app_crypto macros

* Rename `get_keys` to `keys` in BareCryptoStore

* Remove usage of key_pair funcs in tests

* Adjust docstring for *_CYPTO_ID constants

* Fix failures

* Simplify mapping on keys

* Remove one let

* Fixed typo

* PR feedback

* remove whitespace

* Zip keys and signatures

* Use into_iter & remove cloned

* Pass index to MissingSignature

* Use typed errors instead of strings for BareCryptoStore

* Implement Debug for trait error

* Use hashsets for better performance for supported_keys

* Make sure keys are inserted into the keystore

* Make sign_with_all return type consistent with `sign_with`

* Rename Error to BareCryptoStoreError

* Rename CRYPT_TYPE_ID -> CRYPTO_ID

* Remove unnecessary CRYPTO_ID declaration in Public trait

* Convert pub key to CryptoTypePublicPair

* Fix use

* Fix code style

* Implement From on CryptoTypePublicPair in app_crypto macros

* Change CryptoTypePublicPair to a struct

* Implement Display on CryptoTypePublicPair

* Pass CryptoTypePublicPair to MissingSignature error

* Adjust docs according to function signature

* Unify keys implementation

* Fix RPC author tests

* Fix stackoverflow

* Tabify spaces

* Pass KeyTypeId to error for easier debugging

* Fix asserts

* Use ToHex to format public key

* Use constants from sp_core

* Rename testing KeyTypeId constants

* Please compiler

* Restore KeyTypeId names

apparently, they're not only used in tests

* Use BareCryptoStoreError instead of String

* Document return value

* Fix borrow check

* Convert to hashset internally

* WIP - iter_keys

* Return raw_public_keys

* Address PR feedback

* Address PR Feedback

* Fix hexdisplay import error

* Update primitives/core/src/traits.rs

Co-authored-by: Bastian Köcher <[email protected]>