tests(calendar): Add calendar render tests (#3)

- updates calendar to support overriding the current day when rendering
- supports current culture when rendering
- renames Calendar to CalendarGenerator

tests/ModuleTests/Calendar/TestData/CalendarTestDates.cs

@@ -0,0 +1,14 @@
+namespace ModuleTests.Calendar.TestData;
+
+public class CalendarTestDates : TestDataEnumerator<DateTime>
+{
+	public CalendarTestDates()
+	{
+		Data =
+		[
+			new DateTime(2026, 06, 01),
+			new DateTime(2026, 07, 01),
+			new DateTime(2026, 08, 01),
+		];
+	}
+}