[Data Source] Get user stakes

[FrancoAguzzi]

Depending on what the user role is

A stakes list should be taken either from Staking or from Delegate contract.
These user stakes should be get by calling respective Smart-Contract "getUserStakeIds" function.
After this, "stakes(stakeId)" function should be called for each individual stake.
After that, the following data structure should be mounted by a function in the edge of our dApp and Smart-Contract data:

{
  id: string;
  keyper: Address;
  amount: number;
  status: LockStatus;
  unlockDate: number;
}