display external services path (contribs/flows/repo-templates) and be able to restore default values

[clarsonneur]

User story

When we set manually a value for contribs, flows or repo-templates, this information is saved in the workspace, so that we do not need to set it again, next time.

But we forgot that and we became surprised when we do not set it to not be back to what defaults is.

We have 2 options:

• Ensure that if no cli or env variables are set, we restore to default systematically.
• We display the configuration everytime, so that we are aware and if we want to restore to default, we actively define it, with default value.

The 1st option is the more standard one.

The 2nd usually is managed by setting up the change with specific instructions.
like forjj setup repo-templates ... which globally manage the workspace config file. (forjj.json)
As today, this is not the case, that makes the confusion.

I propose to have an intermediate. When we create the forge, (forjj create) from a Forjfile template, we save the local-settings as defined in the forjj.json.
But when we set the cli or env variables, those values are by default choosen, and we restore it back to what was saved in the workspace or to the default if nothing was saved.

And later, we create the forjj setup or forjj worskspace command to update or even edit the workspace file.