Pyethereum keystore support (#9710)

* support for keystore format produced by pyethereum lib + some debug msgs

* made salt unbound also for Scrypt

* made address optional and skip if its none

* ignore values of any type, not just i32

* WIP: local deps

* cleanup

* enable optional address + more cleanup

* yet another cleanup

* enable keystore wo address import (using passwd)

* cleanup

* doc enchancement

* parity/account fix

* redesign after review

* fix indentation

* ignore just version in json under crypto

* remove unnecessary borrowing within match str

Co-Authored-By: tworec <tworec@golem.network>

* remove another unnecessary borrowing

Co-Authored-By: tworec <tworec@golem.network>

* default derived instead of implementing

* log dependency removed

* [ethstore] warn restored + env_logger initialized in CLI

* applied suggestion from @tomusdrw

accounts/ethstore/src/json/kdf.rs

@@ -17,7 +17,7 @@
 use std::fmt;
 use serde::{Serialize, Serializer, Deserialize, Deserializer};
 use serde::de::{Visitor, Error as SerdeError};
-use super::{Error, H256};
+use super::{Error, Bytes};
 
 #[derive(Debug, PartialEq)]
 pub enum KdfSer {
@@ -111,7 +111,7 @@ pub struct Pbkdf2 {
 	pub c: u32,
 	pub dklen: u32,
 	pub prf: Prf,
-	pub salt: H256,
+	pub salt: Bytes,
 }
 
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
@@ -120,7 +120,7 @@ pub struct Scrypt {
 	pub p: u32,
 	pub n: u32,
 	pub r: u32,
-	pub salt: H256,
+	pub salt: Bytes,
 }
 
 #[derive(Debug, PartialEq)]