Driver option to show a help message is all options/flags.

[boschmitt]

Required prerequisites

• Search the issue tracker to check if your feature has already been mentioned or rejected in other issues.

Describe the feature

nvq++ has a help flag which shows a message that contains a "common" subset of all options/flags available. This is fine, we don't want to pollute this message with highly specific, niche options used by advanced users. However, it might be interesting to add another flag which would show all possible options/flags available.