Add method for creating CLI apps from existing sources

[mocenas]

Summary

This PR adds a method to create QuarkusCliRestService from existing sources. It should do similar job as already existing "createApplication" methods.
This feature is important for "quarkus update" testing. For testing advanced scenarios (such as updating entire app with business logic) we need to have prepared app, which we can then update and start. It is not feasible to construct entire app from scratch in tests.

Please check the relevant options

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Dependency update
• Refactoring
• Release (follows conventions described in the RELEASE.md)
• Breaking change (fix or feature that would cause existing functionality to change)
• This change requires a documentation update
• This change requires execution against OCP (use run tests phrase in comment)

Checklist:

• Example scenarios has been updated / added
• Methods and classes used in PR scenarios are meaningful
• Commits are well encapsulated and follow the best practices

[fedinskiy]

1. 3.13.0 is out
2. What about updates and prod versions? I would like to have a way to change this value without editing the file

[mocenas]

This feature is primarily aimed at CLI update-testing. Which means - we want to use old quarkus versions, and if we need up-to-date ones - we'll use "quarkus update" to get to it.
I will add an option to use either CliDevModeVersionLessQuarkusApplicationManagedResource or CliDevModeLocalhostQuarkusApplicationManagedResource (similar to #1232) but I can see potential problems here. See if I have an app with git-anchored sources, then those sources are probably made for specific version of quarkus and changing it to newer version, would possibly require to update the sources as well.

However I can see an use case where overwriting the version in app.start() would make sense. And that is all that matter. I will change it to have this option too.

3.13.0 is out

IMO that doesn't matter. As stated above, this feature is primarily for testing old-version apps, so having one in example is no harm.

[mocenas]

change made.