Improve SDK request evaluator interface

Is your feature request related to a problem? Please describe

The PolicyEvaluation function, when the policy fails, returns an error. The SDK should returns the PolicyResult with Allowed set to false instead, since it is more usable.

rond/sdk/evaluator.go

Lines 97 to 108 in d8c2c8b

    
           // TODO: here if the evaluation result false, it is returned an error. This interface 
        
           // for the sdk should be improved, since it should use the PolicyResult and return error 
        
           // only if there is some error in policy evaluation. 
        
           _, query, err := evaluatorAllowPolicy.PolicyEvaluation(logger, e.policyEvaluationOptions) 
        
           if err != nil { 
        
           	logger.WithField("error", map[string]any{ 
        
           		"policyName": rondConfig.RequestFlow.PolicyName, 
        
           		"message":    err.Error(), 
        
           	}).Error("RBAC policy evaluation failed") 
        
           	return PolicyResult{}, err 
        
           }

	// TODO: here if the evaluation result false, it is returned an error. This interface
	// for the sdk should be improved, since it should use the PolicyResult and return error
	// only if there is some error in policy evaluation.
	_, query, err := evaluatorAllowPolicy.PolicyEvaluation(logger, e.policyEvaluationOptions)

	if err != nil {
	logger.WithField("error", map[string]any{
	"policyName": rondConfig.RequestFlow.PolicyName,
	"message": err.Error(),
	}).Error("RBAC policy evaluation failed")
	return PolicyResult{}, err
	}