Add model Export & Load as part of the full model lifecycle

As part of the full model lifecycle can there be a model export and load API where users provide the model name?

This is quite useful for moving a model from one database to another, performing a "backup and restore" type of operations, etc. Currently, users need to correctly select the relevant rows from each of the pgml catalog tables: pgml.projects, pgml.snapshots, pgml.models, pgml.deployments, pgml.files, etc. And take into account the sequence id fields when inserting. This is cumbersome and prone to error if the API changes, or a new table is introduced, etc.