Implement the "install" action

[imobachgs]

Problem

The api-v2 branch does not implement an action to perform the installation yet.

Solution

• Implement a first and incomplete version of the Install action.
• Move tracking of the installation state (now renamed to Stage) to the progress service.

To do

• Extend the progress service tests to include the stage.
• Rename Get and Set to GetProgress and SetProgress.
• Refuse to run some actions when the state is not Configuring (e.g., SetConfig, RunAction, etc.).

Testing

• Tested manually

[coveralls]

coverage: 61.98%. remained the same
when pulling 8a6ec65 on install
into 51da3da on api-v2.

[mvidner]

Are these user visible?
Translation infrastructure is still missing, but please mark these with gettextrs::gettext and we will make it work later.

[imobachgs]

However, I am not sure about when to do the real translation. Let's think on a theorical case: you are installing the system, or doing the initial probing. You get the messages in, let's say, English. If you change the language, the rest of the process will be emitted in English.

I am tempted of translating the strings later (at API level) but it is true that, at least, we need to mark the strings here. WDYT?

[jreidinger]

is unwrap good idea? It will basically kill that task. I hope for some better handling like at least logging it, or setting some FailedInstall Stage or anything else to indicate that installation failed ( the problem we have with current agama )

[imobachgs]

No, it is not a good idea, but I wanted to have this working to unblock other work on the installation process. I will log the error. Perhaps we could even have a new Stage Error so the UI knows that something went wrong.