TODO: see if more information can be extracted out of 'unmarshall/parsing' errors.

LevelError is for Errors that must be addressed.

LevelWarn is for Errors that should be addressed but do not have to be.

Error is an implementation of the 'error' interface, which represents a warning or an error in a yaml file.

ManifestResult represents verification result for each of the yaml files from the operator manifest.

ErrorType defines what the error resulted from.

Level is the severity of an Error.