fix: improve flag validation

[WillieRuemmele]

@W-13157931@

improves flag validation to prevent a flag being read as a flag value

note: I was unable to get this linked and building through my cli. I took a TDD approach instead and wrote the UTs first, and then fixed them

[shetzel]

QA: ✅
current behavior: sf package:version:create:list -v -s Success --> "No authorization information found for -s"
new behavior: ~/dev/salesforcecli/plugin-packaging/bin/dev package:version:create:list -v -s Success --> "Flag --target-dev-hub expects a value"