Only dequeue Ethereum events from ourselves

[sug0]

When a validator V receives an Ethereum events protocol tx in FinalizeBlock, we should make sure we only dequeue the included events if the signer's address is the same as V's address. Otherwise, we may omit votes for an event, comprimising the liveness properties of the Ethereum bridge (e.g. an event e might never get >2/3 voting power behind it).

Thanks for pointing this out @james-chf

[sug0]

Read on from https://github.com/anoma/namada/pull/817#discussion_r1031544406 for more context