…ically when needing to process blocks that have just been inserted in to the ledger.

Create the block_post_events class who's destructor will execute queued events.

…ks for a given block.

This creates a uniform way to access block dependencies and re implements ledger::could_fit in terms of it.

…number.

…can access more high-level methods.

…sts before votes are actually sent out.

…tion for the first unconfirmed block on an account. It's possible we have a stale branch and won't be able to confirm the frontier so this gives us definite progress.

…tion.

Sequentially voting for blocks decreases the state receivers need to maintain for dependent unconfirmed blocks.

New stat `requests_cannot_vote`, tests updated and a new test added

This appears to be completely unrelated and only hitting on TSAN, likely
a tiny change in thread timings

Update recently added slow_test confirmation_height.many_accounts_send_receive_self

And new elections already get votes generated in the constructor

…k exists

A fix for c581d1a

1. Due to the node wallet creating a block, leading to an unintended
fork with the test block
2. Due to the delay between the vote being inserted in the store and in
the cache

…e the ledger

…polling while holding a mutex

…onfirmed

…oss more complex configurations