Disable schema validation

[simonharrer]

Scenario:

• Edit datacontract.yaml in VS Code
• Visualize the contract on every change using DBML in VS Code

Issue:

• Speed is crucial for a quick update when changing the YAML

Idea:

• add parameter --schema-validation and --no-schema-validation to be able to disable schema validation so the generation of the DBML goes faster. We take into account that errors occur, and the resulting DBML is broken or cannot be produced.