Use nano::test::make_final_vote() instead of manually constructing final votes in unit tests

[dsiganos]

Replace final votes construction of the type:

auto vote (std::make_shared<nano::vote> (nano::dev::genesis_key.pub, nano::dev::genesis_key.prv, nano::vote::timestamp_max, nano::vote::duration_max, std::vector<nano::block_hash> (1, send->hash ())));

with:

nano::test:make_final_vote(nano::dev::genesis_key, { send });

Be careful, we have many types of votes, only replace the final vote generation in this task to keep the change easily reviewable.
There should roughly 10 instances of it.

[RickiNano]

I'm working on this