Update so Firestore field types are correct

addons/godot-firebase/Utilities.gd

@@ -51,6 +51,32 @@ static func dict2fields(dict : Dictionary) -> Dictionary:
 
 	return {'fields' : fields}
 
+class FirebaseTypeConverter extends Reference:
+	var converters = {
+		"nullValue": "_to_null",
+		"booleanValue": "_to_bool",
+		"integerValue": "_to_int",
+		"doubleValue": "_to_float"
+	}
+
+	func convert_value(type, value):
+		if converters.has(type):
+			return call(converters[type], value)
+
+		return value
+
+	func _to_null(value):
+		return null
+
+	func _to_bool(value):
+		return bool(value)
+
+	func _to_int(value):
+		return int(value)
+
+	func _to_float(value):
+		return float(value)
+
 static func from_firebase_type(value):
 	if value == null:
 		return null
@@ -62,7 +88,8 @@ static func from_firebase_type(value):
 	elif value.has("timestampValue"):
 		value = Time.get_datetime_dict_from_datetime_string(value.values()[0], false)
 	else:
-		value = value.values()[0]
+		var converter = FirebaseTypeConverter.new()
+		value = converter.convert_value(value.keys()[0], value.values()[0])
 
 	return value