Add a `role` header to the SWAP REQUEST about rfcs HOT 2 CLOSED

At the moment Alice sends a swap request message to Bob, Bob accepts, Alice starts with funding, etc.

I propose to decouple the swap request from the actual blockchain protocol for RFC003 and rename it (e.g setup phase).

This way, Alice and Bob could switch role with only sending one message, e.g. Alice does not generate the secret but asks Bob for it, now Bob will need to move first with the funding.

I'd be keen to keep our terminology as:

• Alice generates the secret
• Bob does not

So that your proposal would be for Bob to send the message first and ask for the hash to Alice.

from rfcs.

Closing this as this will go aways with the negotiation protocol changes.

from rfcs.