Manifest - Provide a syntax to define common commands flags

[zeralight]

It is common that grouped commands shared some flags.
We can think of --verbose, --quiet, --base-url, --namespace, etc.

> cola jenkins --url https://jenkins.com jobs list
> cola jenkins --url https://jenkins.com credentials list   
...

Today, the concept of group arguments doesn't exist in command-launcher.
Additionally, Yaml list anchors are not supported by the currently used yaml deserialiser.
Hence, we need to redefine each argument for each command.

We should find a better way to avoid redundancy.

[jdevera]

@zeralight This is not a solution, but a hack that I have been using: I have a manifest preprocessor script that generates a valid manifest from my "alternative" manifest.

My alternative manifest has a hierarchy, where groups are the parents of commands, as I understand it better that way. But that is not the point, the point is the method.

The problem I've encountered is that I sometimes forget to preprocess the manifest, and I'm left wondering for a while why something doesn't work.