[IOT-1421] Improve command feedbacks for users

[polldo]

We could return specific types of errors (instead of generic ones) and then depending on it understand what kind of feedback we should give to the user.

Eg:

diff --git a/cli/dashboard/create.go b/cli/dashboard/create.go
index 211dca7..bfcc0d9 100644
--- a/cli/dashboard/create.go
+++ b/cli/dashboard/create.go
@@ -64,13 +64,21 @@ func runCreateCommand(cmd *cobra.Command, args []string) {
 		params.Name = &createFlags.name
 	}
 
-	dashboard, err := dashboard.Create(params)
+	dboard, err := dashboard.Create(params)
 	if err != nil {
-		feedback.Errorf("Error during dashboard create: %v", err)
+		switch err.(type) {
+		case dashboard.ErrMissingName:
+			feedback.Errorf(`Error during dashboard create: %v.
+
+It seems like the provided template doesn't have a default name for the
+dashboard,  please provide one with the --name option."`, err)
+		default:
+			feedback.Errorf("Error during dashboard create: %v", err)
+		}
 		os.Exit(errorcodes.ErrGeneric)
 	}
 
-	feedback.PrintResult(createResult{dashboard})
+	feedback.PrintResult(createResult{dboard})
 }
 
 type createResult struct {
diff --git a/command/dashboard/create.go b/command/dashboard/create.go
index d92c594..ae77261 100644
--- a/command/dashboard/create.go
+++ b/command/dashboard/create.go
@@ -18,13 +18,17 @@
 package dashboard
 
 import (
-	"errors"
-
 	"github.com/arduino/arduino-cloud-cli/internal/config"
 	"github.com/arduino/arduino-cloud-cli/internal/iot"
 	"github.com/arduino/arduino-cloud-cli/internal/template"
 )
 
+type ErrMissingName struct{}
+
+func (ErrMissingName) Error() string {
+	return "dashboard name not specified"
+}
+
 // CreateParams contains the parameters needed to create a new dashboard.
 type CreateParams struct {
 	Name     *string           // Name of the new dashboard
@@ -54,7 +58,7 @@ func Create(params *CreateParams) (*DashboardInfo, error) {
 	}
 	// If name is not specified in the template, it should be passed as parameter
 	if dashboard.Name == "" {
-		return nil, errors.New("dashboard name not specified")
+		return nil, ErrMissingName{}
 	}
 
 	newDashboard, err := iotClient.DashboardCreate(dashboard)

Originally posted by @glumia in #50 (comment)