Nomad `BridgeRouter` is liquidity holder

[LayneHaber]

Problem Refactor to use Nomad BridgeRouter as core interface to nomad messaging/assets. Transfers will be initiated with the Connext contract.

Ideas to solve this Refactor to:

1. user calls xcall

• xcall swaps into local
• sends local asset to nomad bridge router via calling send
• bridge router burns tokens
• bridge router creates + dispatches message

2. relayer calls execute (0 changes here)
3. bridge router receives nomad message, transfers to connext, calls reconcile on connext which then does the exact same stuff it does now

Acceptance Criteria

• [ ] Connext plugs into bridge router
• [x] Bridge router pr accepted into nomad: https://github.com/nomad-xyz/monorepo/pull/371

Other