EVM Kernel: Fix reimbursement to the sequencer pool address

Context

The failsafe storage mechanism implemented recently is quite subtle (and error-prone). During the production of a block, /evm/world_state is copied to /tmp/evm/world_state and every access to the durable storage is prefixed by /tmp. This is why the configuration is passed over in the various block validation function. This logic was not used for the sequencer pool address, which is read in place at /evm/sequencer_pool_address (that is, /tmp/evm/sequencer_pool_address).

We fix this bug by reading the sequencer pool address once, before starting the block production, and passing the argument over to use site.

Manually testing the MR

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
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