## Issue Addressed
Closes#1823
## Proposed Changes
* Use OS-level file locking for validator keystores, eliminating problems with lockfiles lingering after ungraceful shutdowns (`SIGKILL`, power outage). I'm using the `fs2` crate because it's cross-platform (unlike `file-lock`), and it seems to have the most downloads on crates.io.
* Deprecate + disable `--delete-lockfiles` CLI param, it's no longer necessary
* Delete the `validator_dir::Manager`, as it was mostly dead code and was only used in the `validator list` command, which has been rewritten to read the validator definitions YAML instead.
## Additional Info
Tested on:
- [x] Linux
- [x] macOS
- [x] Docker Linux
- [x] Docker macOS
- [ ] Windows
## Issue Addressed
Closes#1889
## Proposed Changes
- Error when passwords which use invalid UTF-8 characters during encryption.
- Add some tests
## Additional Info
I've decided to error when bad characters are used to create/encrypt a keystore but think we should allow them during decryption since either the keystore was created
- with invalid UTF-8 characters (possibly by another client or someone whose password is random bytes) in which case we'd want them to be able to decrypt their keystore using the right key.
- without invalid characters then the password checksum would almost certainly fail.
Happy to add them to decryption if we want to make the decryption more trigger happy 😋 , it would only be a one line change and would tell the user which character index is causing the issue.
See https://eips.ethereum.org/EIPS/eip-2335#password-requirements
