Fix history generation and optimise via pre-sorting in the files (#572)

* Rewrite

* Fix linter, make counter

* Skip hash stage

* Fix linter

* Add common

* Fix wrong bucket

* Use temp files to generate index

* Fix hack, defer

* Add logging when creating files

* Properly pass datadir

* Bigger buffers, less logging

* Log current key, enforce batching

* Limit to 4m, print more

* Use ReadFull

* Optimised version of storage generation

* Don't print entire key

* Commit at the end

* Fix linter

* Remove a bit of copy-paste

* More copy-paste reduction

* Fixes

* Fix key length

* Not delete files too early

* Fix linter

* Fix logging

* Fix starting block

* Skip test

* Remove limit on the stage 4

* Fix test while disabling the hash check

* Fix tests

* Fix unreachable