Add utility function for parsing properties lists

Used as a convention for years, the integer terminal subproperty's use as an array syntax has now been formalized as a
"list" type. Although the properties package provides a function to parse this data type, it still takes some code
acrobatics to convert that into the map[string]interface{} type consumed by the JSON schema parser, which is a candidate
for a function.

Another "set" data type has also been added, but I don't have an immediate need for it, so will wait to add
support.

Author: per1234

internal/project/general/general.go

@@ -51,3 +51,17 @@ func PropertiesToMap(flatProperties *properties.Map, levels int) map[string]inte
 
 	return propertiesInterface
 }
+
+// PropertiesToList parses a property that has a list data type and returns it in the map[string]interface{} type
+// consumed by the JSON schema parser.
+func PropertiesToList(flatProperties *properties.Map, key string) map[string]interface{} {
+	list := flatProperties.ExtractSubIndexLists(key)
+	// Convert the slice to the required interface type
+	listInterface := make([]interface{}, len(list))
+	for i, v := range list {
+		listInterface[i] = v
+	}
+	mapInterface := make(map[string]interface{})
+	mapInterface[key] = listInterface
+	return mapInterface
+}

internal/project/general/general_test.go

@@ -102,3 +102,23 @@ func TestPropertiesToMap(t *testing.T) {
 	assert.True(t, reflect.DeepEqual(expectedMapOutput, PropertiesToMap(propertiesInput, 3)))
 	assert.True(t, reflect.DeepEqual(expectedMapOutput, PropertiesToMap(propertiesInput, 0)))
 }
+
+func TestPropertiesToList(t *testing.T) {
+	rawProperties := []byte(`
+		hello=world
+		foo.1=asdf
+		foo.2=zxcv
+	`)
+	propertiesInput, err := properties.LoadFromBytes(rawProperties)
+	require.Nil(t, err)
+
+	expectedMapOutput := map[string]interface{}{
+		"hello": []interface{}{"world"},
+	}
+	assert.True(t, reflect.DeepEqual(expectedMapOutput, PropertiesToList(propertiesInput, "hello")))
+
+	expectedMapOutput = map[string]interface{}{
+		"foo": []interface{}{"asdf", "zxcv"},
+	}
+	assert.True(t, reflect.DeepEqual(expectedMapOutput, PropertiesToList(propertiesInput, "foo")))
+}