Ensure the correct network is always used for signing/polling EVM transactions

[Sharqiewicz]

Discussed in this PR: PR #480

During the SquidRouter phase, we rely on wagmi to interact with the blockchain network currently selected by the user. The offramp process is initiated based on the network chosen by the user at the start. However, if the user switches the network in their wallet during the SquidRouter phase, the entire process could break.

To address this, the goal is to save the network on which the offramp was initially started and consistently use it throughout the SquidRouter phase, rather than dynamically relying on the user's current network setting. This ensures the process remains stable even if the user changes the network in their wallet mid-transaction.

[prayagd]

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