[IBD/Rewind] Optimize VotingManager for batched operations

[quantumagi]

https://app.clickup.com/t/20r2acb

Addresses the following:

        "BlockConnected" average total execution time: 15.6064 ms.
            ReserveUtxoService.OnBlockConnected-------------------------0.0038 ms---0 %
            MempoolSignaled.OnBlockConnected----------------------------0.0033 ms---0 %
            WalletSyncManager.OnBlockConnected--------------------------0.0013 ms---0 %
            BlockStoreSignaled.OnBlockConnected-------------------------0.0133 ms---0 %
            EventSubscriptionService.<Init>g__callback|6_0--------------0.1138 ms---1 %
            VotingManager.OnBlockConnected------------------------------15.4709 ms--99 %

By allowing the VM to lag during IBD we can move away from the current scenario of only processing one block at a time (and committing to the DB each time). Decreasing the number of commits cuts hours off the IBD process.