integration: fix problem with interruption (#743)

* store stageData correctly

* integration: use State of sync, use stage data, don't skip persistent steps even if they complete before interruption

* reset_state: clear unwind stages info

* stage4: stop where previous stage stopped, print to logs digits which represent what exactly is in DB, rename variable 'nextBlockNumber' to 'stateProgress'

* rebase to master

* simplify chainconfig

* try increase sleep time on ci

* try increase sleep time on ci

* try increase sleep time on ci

* try increase sleep time on ci