Create Token Payment Interface

[enyinnaya1234]

Implement Stark Token Payment System

Description

The platform requires handling Stark token payments for subscriptions and purchases. We need to implement the token integration for the payment system.

Requirements

• Interface with Stark token contract
• Handle token transfers for subscriptions and purchases
• Implement secure payment verification
• Create payment history tracking

Implementation Details

// Import token interface
use openzeppelin::token::erc20::interface::IERC20;

// Add to Storage struct
token_address: ContractAddress,

// New functions
fn set_payment_token(ref self: TContractState, token_address: ContractAddress);
fn process_payment(ref self: TContractState, amount: u256) -> bool;
fn get_payment_history(self: @TContractState, user: ContractAddress) -> Array<Payment>;