Bridges testing improvements (#6536)
This PR includes:
- Refactored integrity tests to support standalone deployment of
`pallet-bridge-messages`.
- Refactored the `open_and_close_bridge_works` test case to support
multiple scenarios, such as:
1. A local chain opening a bridge.
2. Sibling parachains opening a bridge.
3. The relay chain opening a bridge.
- Previously, we added instance support for `pallet-bridge-relayer` but
overlooked updating the `DeliveryConfirmationPaymentsAdapter`.
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Co-authored-by: GitHub Action <[email protected]>