Implement decentralized exchange pool base on Uniswap VIA rust and substrate

[4his2]

Enhancement

• [ ] Support "add liquidity" and "remove liquidity"
• [ ] Support "mint" and "burn"
• [ ] Support "transfer" and "approval"

[armatrix]

I will contribute the following modules:

1. swap_with_exact_supply
2. swap_with_exact_target
3. add_liquidity
4. remove_liquidity
5. new_trading_pair & enable_trading_pair & disable_trading_pair

[armatrix]

Event Type:

    #[pallet::event]
    #[pallet::generate_deposit(pub (crate) fn deposit_event)]
    pub enum Event<T: Config> {
        AddPreparing(T::AccountId, CurrencyId, Balance, CurrencyId, Balance),

        AddLiquidity(T::AccountId, CurrencyId, Balance, CurrencyId, Balance, Balance),

        RemoveLiquidity(T::AccountId, CurrencyId, Balance, CurrencyId, Balance, Balance),

        Swap(T::AccountId, CurrencyIds, Balance, Balance),

        EnableTradingPair(TradingPair),

        NewTradingPair(TradingPair),

        DisableTradingPair(TradingPair),

        PreparingToEnabled(TradingPair, Balance, Balance, Balance),
    }