More accurate gas estimation on MixedQuoterV2

[chefburger]

          lets create GH issue on this and take it from there. 

1. Fixing it in this PR will expand the scope
2. its used by FE so we can eventually do a MixedQuoterV2 with proper gas estimate for v2 and stableswap

Originally posted by @ChefMist in https://github.com/pancakeswap/pancake-v4-periphery/pull/32#discussion_r1798906247