Import of Data Models

**Is your feature request related to a problem? Please describe.**
It would be awesome if there was a mechanism to import data models, either from standard DB schema exports or from excel, csv, XML, JSON. It is very slow to make large DB schemas or to migrate from a legacy database.

**Describe the solution you'd like**
Rather than having to use the CLI, it would be awesome to import schema in various formats.

**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features you've considered.
I have used the CLI to modify the schemas but this is still slow and manual.

**Additional context**
Add any other context or screenshots about the feature request here.

The issue names no files or tests. Start by surveying the existing CLI schema workflow and how data models are represented, then determine which standard DB, Excel, CSV, XML, and JSON inputs are in scope; done would require an agreed import design and working support for the selected formats.

Written by the indexing model from the issue text.