Create an option to disable specific parts of validation

[alanbo]

aws/aws-toolkit-vscode#1102
aws/aws-toolkit-vscode#1016

Create options to disable:

• Validation based on JSON Schema
• Validation of additional properties
• Validation of Parameters

Thanks to that we would be able to limit the validation for state machine renderer in AWS Toolkit for VS Code. Users at times may want to render invalid ASL.