[CLI] lb model should prompt repository selection/creation

[hacksparrow]

Description / Steps to reproduce / Feature proposal

Create a new model using lb model.

Current Behavior

Only model files are generated.

Expected Behavior

Should prompt the user to either:

• Link an existing repository to the model
• Create a new repository for the model

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[virkt25]

With LoopBack 4, one of the intentions is to move away from having a Model tied to a DataSource. We should be able to use model with multiple repositories if needed. As such I don't think lb4 model should be prompting for or trying to link a model to a repository but rather lb4 repository (when introduced) should be doing the linking between a model, and datasource to create an appropriate repository.

That said ... maybe this signifies that we eventually need a command to create a series of artifacts together since in most cases you'll want to create a model followed by a repository and controller for the model ... so a new command to streamline this process might be helpful but I don't know if it should be done via lb4 model ... maybe a new command of sorts but I can't think of a good name.

[bajtos]

Let's close this as a duplicate of #1588