Add getR2dbcurl to interface

Author: jan-knoblich

modules/r2dbc/src/main/java/org/testcontainers/r2dbc/R2DBCDatabaseContainer.java

@@ -5,4 +5,17 @@
 
 public interface R2DBCDatabaseContainer extends Startable {
     ConnectionFactoryOptions configure(ConnectionFactoryOptions options);
+
+    /**
+     * Returns the R2DBC URL for connecting to the database.
+     * <p>
+     * The default implementation throws {@link UnsupportedOperationException}.
+     * Implementations should override this method to provide the actual R2DBC URL.
+     *
+     * @return the R2DBC URL in the format: r2dbc:driver://username:password@host:port/database
+     * @throws UnsupportedOperationException if the implementation does not support R2DBC URLs
+     */
+    default String getR2dbcUrl() {
+        throw new UnsupportedOperationException("R2DBC URL is not supported by this container");
+    }
 }