Tri hops with mid pool

[johngrantuk]

• Adds 3 hop path creation through mid pools added to config under triPathMidPoolIds
• Add Base config for examples with triPathMidPoolIds staBal pool added

Path creation:
For each midpool construct construct 3 hop paths like: tokenIn[poolA]tokenA[MidPool]tokenB[poolB]tokenOut.

• tokenA/B are midpool pool tokens
• poolA/B are most liquid pools connecting tokenIn/Out to tokenA/B
• We only want to use a pool as middle hop if tokenIn/Out aren't it's pool tokens as normal algo should take care of that path.

To test:
On production UI, Base network, try a swap between DAI>BALD - currently it doesn't find a liquid path as we need to do a 3 hop non-boosted path.
Run SOR swapExample (need to add RPC_URL_BASE=https://mainnet.base.org to .env) - it should find a valid path.

[brunoguerios]

LGTM! Solution seems pretty straightforward and example works as expected on my end. ✅