Enable Factory Fee

[0xAleksaOpacic]

✨ Feature Request

Description

In the current implementation, _mintFee is [disabled](https://github.com/NilFoundation/uniswap-v2-nil/blob/main/contracts/UniswapV2Pair.sol#L82).

The reason for this is that the factory can be deployed on another shard, which may cause issues when fetching feeOn from the factory contract.

We need to enable fees, and there are multiple possible implementations to consider:

1. Manually setting feeOn in each pair
2. Creating a gossip mechanism from the factory to update all pairs

We need to adapt:
1. Factory contract
2. Write task for managing fees

Use Case

In Uniswap V2, the feeTo mechanism is included as part of the protocol's ability to capture a portion of the trading fees. While by
default, no fees are collected by Uniswap V2, the feeTo parameter allows the governance or controlling party (e.g., a DAO or
centralized entity) to activate a fee switch in the future.