Add support for PancakeSwap v3

[beeb]

• [x] I have searched the issues of this repo and believe that this is not a duplicate.
• [x] I have read the Readme and believe that my question is not covered.

Feature Request

Add support for PancakeSwap v3.

The new router (0x13f4EA83D0bd40E75C8222255bc855a974568Dd4) has backwards support for V2 liquidity by calling the multicall function and using the old swapExactTokensForTokens and swapTokensForExactTokens optionally combined with unwrapWETH9.

Would this be a good time to think to "Rewrite it in rust"™ ?

[chicken2019]

I'm happy if you make a version for pancakeswap v3