Increase reuse of ModelConfig

[avishniakov]

Describe changes

This PR removes ModelConfigModel; all codes now use ModelConfig instead. ModelConfig now has a model and model_version to avoid multiple calls to DB while working inside the same context.
ModelConfig is still instantiated on every step due to how reading of configs from DB works currently - it gets a dict and converts to_model where applicable, but no extra calls to DB are done with the current architecture.

Pre-requisites

Please ensure you have done the following:

• I have read the CONTRIBUTING.md document.
• If my change requires a change to docs, I have updated the documentation accordingly.
• If I have added an integration, I have updated the integrations table and the corresponding website section.
• I have added tests to cover my changes.
• I have based my new branch on develop and the open PR targets develop. If your branch wasn't based on develop read Contribution guide on rebasing branch to develop.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Other (add details above)

[fa9r]

Nice, this feels much cleaner 🙌

Just have a few more minor suggestions, otherwise this looks good to merge 👍

[fa9r]

This feels a bit weird, why can't we use None as default / latest value instead?

[avishniakov]

Cause it is strings - cli arguments and -1 which I planned to use is treated as a parameter name, so 0 seemed a solid choice. Moreover - user will not specify it directly, it will be set by just skipping this arg.
zenml model version artifacts my_model -> will return artifacts for latest in my_model

[fa9r]

I don't get it, why can't it be Optional[str] instead? I.e., why would this not work?

@click.argument("model_name_or_id")
@click.argument("model_version_name_or_number_or_id")
def list_model_version_artifacts(
    model_name_or_id: str,
    model_version_name_or_number_or_id: Optional[str] = None,
) -> None:
    ...

def _print_artifacts_links_generic(
    model_name_or_id: str,
    model_version_name_or_number_or_id: Optional[str] = None,
    ...
):
    ...

[avishniakov]

It is a click limitation, as I see this. If I set default=None it is treated as no default, making arg mandatory. Changes on the level of functions args are not effective at all - @click.argument is the king here.

[fa9r]

Ah, yes, click.argument means mandatory, for optional inputs you need to use click.option

[avishniakov]

Nah, the option would lead to the argument passing as --model_version_name_or_number_or_id and not just zenml some_command some_argument [some_skipped_optional_argument] or I completely misuse click 🙂

[strickvl]

Looks great + lovely to have it well tested, too.