Remove synchronizer dependency from EthTxManager

[tclemos]

Currently, after checking whether a TX was mined, the EthTxManager waits for the synchronizer to synchronize the block where the TX was mined to confirm it. This makes the EthTxManager totally coupled to the Synchronizer and makes it to hand when using the Synchronizer with a Safe point far from the tip. The side effect of it is the network getting slow to virtualize blocks when there are a lot of batches to virtualize.