Allow multiple addresses to incentivize a packet

[AdityaSripal]

• Include the refund address in the key of the stored fee. packetID + refund_addr -> accumulated fees escrowed by this sender for this packetID + relayer list
• On distribution, loop through all fees stored for a given packetID and execute the distribution logic with the same relayers for each refund address.

[colin-axner]

What happens if the same funder tries to incentivize a packet but specifies a different relayer list?

If we wanted to allow this, we should be mapping to a slice of identified packet fees, but then I'm wondering why we don't just map from packetID -> []identified packet fee (with refund address)

Was there a security concern with not including the refund address in the key?

[colin-axner]

Do we want the refund addr in the key or identified fee struct? It shouldn't be both. It is convenient for it to be in the mapping, but you can filter based on incentivizer if it is in the key

[AdityaSripal]

I think the map from packetID -> []identified packet fee (with refund address) solution makes the most sense

I don't think it's that important to additionally key on refund address, especially if the first prefix is packetID

[damiannolan]

closed by #915