[APICTL] Introduce a Schema for Params.yaml

[npamudika]

Current Limitation

Currently we do the validation for fields in the params.yaml in the code level itself (refer https://github.com/wso2/carbon-apimgt/blob/master/components/apimgt/org.wso2.carbon.apimgt.rest.api.publisher.v1.common/src/main/java/org/wso2/carbon/apimgt/rest/api/publisher/v1/common/mappings/APIControllerUtil.java#L352 for example). So when showing errors in the params.yaml it gives a general output.

Suggested Improvement

Incorporate a schema file when validating the params.yaml so that the error messages can also be improved.

Version

No response