Allow importing local repository snapshots

[lbroudoux]

Reason/Context

As Microcks allows import of standard artifacts, it also allow loading repository snapshots as described in the documentation here: https://microcks.io/documentation/administrating/snapshots/

Snapshots are lightweight structures that can be used to:

• easily exchange a set of Services & APIs definitions with another instance of Microcks,
• easily setup a new Microcks instance dedicated to mocking a functional subsystem - optionally with different configured response times for simulating a real behavior,
• easily backup your instance if you do not bother losing tests runs and analytics data

Description

We want a new withSnapshots(String... snapshotPath) method that allows specifying snapshots to load at container startup.

We also want a specific importSnapshot(File snapshotFile) generic method that can be used after container startup.

Beware that due to their nature, snapshots should loaded first before loading any other artifacts at startup. Artifacts may then override existing parts of services loaded from snapshots. If explicitly imported after the startup, a snapshot may then delete customization done by artifacts.

Implementation ideas

No response

[lbroudoux]

It must also provide a fallback method like in #45