Support for executor = TAKER flows

[bam4564]

The RFQ system supports two kinds of flows executor = MAKER -> user connected to /maker namespace calls seaport.fulfillOrder executor = TAKER -> user connected to /taker namespace calls seaport.fulfillOrder

The executor is specified when creating the RFQ and partially determines the structure of data payloads in events emitted from the server. The taker and maker providers should be listening for all events required regardless of RFQ executor type.

For the taker provider

• Add in a listener for the OrderCreated event. See method on_OrderCreated here
• Add in a listener for the OrderFulfilled event.

For the maker provider

• Add in a listener for the QuoteAccepted event. See method on_QuoteAccepted here