[TODO] add validate command

[ITProKyle]

Summary

A command to validate modules/configuration files.

Why This Is Needed

Consolidate IaC validation functionality into a single command that can be run through the standard Runway workflow. Without this, if someone wanted to validate a module, they would need to cd into the module directory and manually account for what Runway adds when running validation.

Tasks

• add validate command
• add validate command handling to deployment/module processing
• add .validate() method to all module classes - log that it's not supported for the time being
• add logic to validate Runway config file (check against schema/parse with pydantic)
• add logic to CDK .validate() method
• add logic to Cloudformation .validate() method
  • determine how CFNgin should go about validating (at a minimum, check config against schema/parse with pydantic)
• add logic to Kubernetes .validate() method
• add logic to Serverless .validate() method
• add logic to staticsite .validate() method
• add logic to Terraform .validate() method