feat: Skip fee policies for TWAP orders

[sunce86]

Problem

TWAP orders are limit orders. Since we initially don't want to charge fees for TWAP orders (and once we eventually do, the policy will probably be different from regular limit orders (regular limit order will be charged on quote deviation fee and TWAP orders on volume based fee), then we need to skip TWAP orders when we define fee policy on each auction.

Suggested solution

We need a way to differentiate between limit orders and TWAP orders. Once we have that, just set the empty fee policy for them.

[sunce86]

Update: TWAP orders are limit orders with high slippage (~ 10%). For initial protocol fee launch (where we charge for out-of-market limit orders), TWAP orders will be treated the same way as all other limit orders. No custom implementation is needed for them.