[FEATURE] have error code and chaining for deployment validate cmd

[dennisseah]

closes microsoft/bedrock#1291

also fix typos
rename validation.md => validate.md and validation.decorator.json => validate.decorator.json because they are named incorrectly

[samiyaakhtar]

Would be nice to run the integration test for this logic (for changes in spk deployment create command)

[dennisseah]

Would be nice to run the integration test for this logic (for changes in spk deployment create command)

which integration test has this command, I did a grep and cannot find it. thanks

[samiyaakhtar]

The integration tests create pipelines which use this command, so it's not directly called from the integration test files. I think you can merge and if something breaks, we will see. :)