Accessibility: Explicitly implement protocols

This change is intended to resolve an issue where iOS apps failed
automated review due to use of non-public selectors. Explicitly adopting
the relevant protocols allowed an app to pass automated review during
testing.

modules/juce_gui_basics/native/accessibility/juce_ios_Accessibility.mm

@@ -225,8 +225,11 @@ private:
                 addMethod (@selector (accessibilityDataTableCellElementForRow:column:), getAccessibilityDataTableCellElementForRowColumn);
                 addMethod (@selector (accessibilityRowCount),                           getAccessibilityRowCount);
                 addMethod (@selector (accessibilityColumnCount),                        getAccessibilityColumnCount);
+                addProtocol (@protocol (UIAccessibilityContainerDataTable));
+
                 addMethod (@selector (accessibilityRowRange),                           getAccessibilityRowIndexRange);
                 addMethod (@selector (accessibilityColumnRange),                        getAccessibilityColumnIndexRange);
+                addProtocol (@protocol (UIAccessibilityContainerDataTableCell));
             }
            #endif