* Mostly atomic put_state() * Reduce number of vec allocations * Make crucial db operations atomic * Save restore points * Remove StateBatch * Merge two HotColdDB impls * Further reduce allocations * Review feedback * Silence clippy warning
* Mostly atomic put_state() * Reduce number of vec allocations * Make crucial db operations atomic * Save restore points * Remove StateBatch * Merge two HotColdDB impls * Further reduce allocations * Review feedback * Silence clippy warning