* fix(state): mark DiskWriteBatch as must_use
* doc(state): add TODOs for moving database reads to blocking threads
* doc(state): minor comment tweaks
* refactor(state): split write batch into block, transactions, chain history
* refactor(state): split out a genesis block write method
* refactor(state): just use the empty note commitment trees directly
* refactor(state): split transaction writes into transparent, nullifiers, trees
And change DiskWriteBatch methods to take `&mut self`.
* refactor(state): split chain value pool writes out of history writes
* refactor(state): combine note commitment trees into an agrument struct
* refactor(state): split history and note commitment updates
* refactor(state): calculate current tip height and remove that argument
* refactor(state): move disk_db reads to a new zebra_db module
* refactor(state): make finalized value pool method names consistent
* refactor(state): split database writes into the zebra_db module
* refactor(state): move the block batch method to DiskWriteBatch
* refactor(state): actually add the zebra_db module
Unfortunately, I've lost the interim changes to this file,
so this commit might be the only one that compiles.
* refactor(state): add a newly created file to the cached state CI job
teor