adds constraints config to model yml file

[Victoriapm]

resolves #102

This is a:

• [ ] documentation update
• [ ] bug fix with no breaking changes
• [x] new functionality
• [ ] a breaking change

All pull requests from community contributors should target the main branch (default).

Description & motivation

Including amn option to configure the constraints in a model yml by retrieving the data types of the columns.

Checklist

• [ ] This code is associated with an issue which has been triaged and accepted for development.
• [ ] I have verified that these changes work locally
• [ ] I have updated the README.md (if applicable)
• [ ] I have added tests & descriptions to my models (and macros if applicable)
• [ ] I have added an entry to CHANGELOG.md

[Victoriapm]

Still missing to update docs and only tested locally with BigQuery, yet to test locally using Snowflake and Postgres

[github-actions[bot]]

This PR has been marked as Stale because it has been open with no activity as of late. If you would like the PR to remain open, please comment on the PR or else it will be closed in 7 days.

[github-actions[bot]]

Although we are closing this PR as stale, it can still be reopened to continue development. Just add a comment to notify the maintainers.