The man generation would generate suggestions for all options of
values they should take, even if the argument did not take values.
This adds a simple check to make sure only options that take values
offer a suggestion

fixes: clap-rs#4443

It was noticed that between clap-rs#4443 and clap-rs#4432, an issue in the behavior
was that the derive api handles tasks with values slightly differently
than the declarative api. Added a test to show parity between
declaritive and derive api.