Add moveToTable context menu action and extract tableRowToGridY helper (#6738)

Adds a Table option to the Move menu, allowing cards to be moved directly to the battlefield from any zone. Extracts the repeated tableRow-to-grid-Y conversion logic into TableZone::tableRowToGridY(), consolidating five call sites and fixing a latent bug where cards with tableRow > 2 could land on the wrong row.

cockatrice/src/game/zones/table_zone.cpp

@@ -382,3 +382,11 @@ int TableZone::clampValidTableRow(const int row)
         return TABLEROWS - 1;
     return row;
 }
+
+int TableZone::tableRowToGridY(int tableRow)
+{
+    if (tableRow > 2) {
+        tableRow = 1;
+    }
+    return clampValidTableRow(2 - tableRow);
+}