fix(grid): Enter 键优先选中自动补全建议项 (closes #202)

WHERE 和 ORDER BY 输入框中，有自动补全建议显示时按 Enter 键
现在会选中当前高亮的建议项，而不是直接执行查询。

src/components/grid/DataGrid.vue

@@ -623,6 +623,10 @@ function onWhereFilterKeydown(e: KeyboardEvent) {
   }
   if (e.key === "Enter") {
     e.preventDefault();
+    if (whereSuggestions.value.length > 0) {
+      acceptWhereSuggestion();
+      return;
+    }
     applyWhereFilter();
   }
 }
@@ -709,6 +713,10 @@ function onOrderByKeydown(e: KeyboardEvent) {
   }
   if (e.key === "Enter") {
     e.preventDefault();
+    if (orderBySuggestions.value.length > 0) {
+      acceptOrderBySuggestion();
+      return;
+    }
     applyOrderBySearch();
   }
 }