Add support for multiple connection hops in tx chan-open-init

[romac]

Summary

tx chan-open-init

• Add --connection-hops=conn1,conn2,conn3 parameter to tx chan-open-init
• Define ConnectionHop struct
• Define ConnectionHops struct initially with single field hops: Vec<ConnectionHop>
• Fetch alls connections and store them in ConnectionHops
  • 1. Fetch destination connection (--dst-connection) on the destination
  • 2. Fetch the client state for the client underlying that connection on the destination chain
  • 3. Get the counterparty chain id from the client state
  • 4. Do this for all connection hops, from last to first
• Add connection_hops: ConnectionHops field to Channel struct
• Add support for connection hops to Channel::build_chan_open_init_and_send
  • Change connection_id field on struct Attributes to a Vec<ConnectionId>
  • Parse connection_ids from channel_open_init event into Attributes.connection_id
• Write unit tests for tx chan-open-init with --connection-hops
• Write integration test for single hop channel

struct ConnectionHop {
  pub connection: IdentifiedConnectionEnd,
  pub client_state: AnyClientState,
  pub reference_chain_id: ChainId,
}

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