Add v4-router

[saucepoint]

https://github.com/z0r0z/v4-router

replace PoolSwapTest in the tests with UniswapV4Router04

[cristianopolicarpo]

Yes, it looks good.

[cristianopolicarpo]

Hey @saucepoint, I installed v4-router in v4-template but got Foundry errors “Invalid implicit conversion” from duplicate v4-core, v4-periphery, and permit2 copies.