Refactor configuration for scord and scord-ctl

scord:
- Configuration file now uses standard YAML format

scord-ctl:
- Add `--output` CLI argument
- Add `--listen` CLI argument (Fixes #126)
- Remove configuration file

Both:
- Remove file_options dependency
- Remove genopts dependency
- Replace yaml-cpp with rapidyaml
- Replace general settings with specific configurations (fixes #20)
- General improvements and bugfixes in `logger`
- Improved `net::server` configuration
- Fix fork()-related bug in `signal_listener`
- Remove environment variables