internal/rosa: check name uniqueness

This should prevent adding packages with nonunique names.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/all_test.go

@@ -51,3 +51,16 @@ func TestResolveNameUnexported(t *testing.T) {
 		})
 	}
 }
+
+func TestUnique(t *testing.T) {
+	t.Parallel()
+
+	names := make(map[string]struct{})
+	for i := range rosa.PresetEnd {
+		name := rosa.GetMetadata(rosa.PArtifact(i)).Name
+		if _, ok := names[name]; ok {
+			t.Fatalf("name %s is not unique", name)
+		}
+		names[name] = struct{}{}
+	}
+}