Add VirtualEntityOptions and EntityOptions records

Introduced two new record types: VirtualEntityOptions (currently empty) and EntityOptions, which encapsulates a Table instance. These additions lay groundwork for future entity configuration options.

src/ReC.Infrastructure/Options/Table.cs

@@ -3,4 +3,10 @@
 public record Table(
     string Name,
     string? Schema = null
-);
+);
+
+public record VirtualEntityOptions
+{
+}
+
+public record EntityOptions(Table Table);