db: remove wal disabling / fast-and-loose option. (#8963)

* parity: highlight --fast-and-loose is not recommended.

* parity: remove fast-and-loose option, ref #1765

* db: remove db wal from options, it's always enabled

* db: remove wal from rocksdb helpers

* cli: fix wallet import test

* ethcore: fix client config tests

* parity: proper deprecated handling for fast-and-loose

* ethcore-client: fix config

* parity: mark fast-and-loose removed

* parity: fix test_find_deprecated

* parity: fix type for fast-and-loose flag

* lock file