* rpc: generate new account id for imported wallets
* ethstore: handle duplicate wallet filenames
* ethstore: simplify deduplication of wallet file names
* ethstore: do not dedup wallet filenames on update
* ethstore: fix minor grumbles
* created the dir crate in util
* moved code from ethstore/src/dir/paths.rs to dir crate
* rename dir module in ethstore to accounts_dir to distinguish it
from the dir crate
* changes after @tomusdrw on #6952