VDA token swaps

[tahpot]

Add support for VDA token swaps.

[ITStar10]

In general, to swap tokens from one to another, tokens should be connected in swapping pools.
There can be several swaps in a chain and individual Swap(for example Pancake in Binance) has their pools. 'Pool' is a pair of 2 tokens. For example, if there are pools of 'A'-'B' and 'B'-'C', token 'A' can be swapped into 'C'. This is swapping inside a chain.
To swap tokens crossing chains, bridging should be implemented first.
Another one to consider in the cross-chain swap is cross-chain pools. These pools consist of several tokens. O3Swap is a cross-chain swap using Poly network, and it created 7 cross-chain pools (https://o3swap.com/hub).
By the way, to support swap for VDA tokens, we need to create pools in a swap on each chain first.

[tahpot]

@ITStar10

Just to confirm. We don't need to do any development work here, we just need to choose a swap protocol (ie; Uniswap) and add liquidity.

Correct?