Implement account creation methods

[jeevanpillay0000]

Is your feature request related to a problem? Please describe.
Start by implementing the required methods and codes for accounts to be created respectively to their blockchains

Describe the solution you'd like:
Must be able to create a new account, also convert existing keys as well to their account implementation. Also, implement TypeAccount interface that governs all key types.

type TypeAccount = { privateKey: string; address: string; encryption: string };

Supported Methods:
public createAccount(): TypeAccount
public privateKeyToAccount(key: Buffer): TypeAccount

Supported by:
Vechain
Ethereum