Retrieve ETH withdrawal history

[HDauven]

Is your feature request related to a problem? Please describe.
The ability to retrieve ETH withdrawal history for a given address on the Nahmii bridge.

Describe the solution you'd like
For the SDK to expose a function that filters on ETH withdrawals directed towards the Nahmii bridge. Filtering can be done on events emitted by the bridge contract.

Additional context
There is a distinction between ETH and ERC20 deposits/withdrawals, which has to be accounted for by providing different functions for each.

Stepwise breakdown

• Filter on L2 bridge events, where the event is WithdrawalInitiated.
• Filter out non-ETH tokens from the events list, where the token arguments equal the NVM ETH predeploy for the L2 token and a zero address for the L1 token.
• Return structured events data to the API consumer.

Definition of done

• The SDK provides a function that returns the ETH withdrawals for a given address.