## Issue Addressed
#2224
## Proposed Changes
Add a `--password-file` option to the `lighthouse account validator import` command. The flag requires `--reuse-password` and will copy the password over to the `validator_definitions.yml` file. I used #2070 as a guide for validating the password as UTF-8 and stripping newlines.
## Additional Info
Co-authored-by: realbigsean <seananderson33@gmail.com>