添加了变量表的停用和启用功能，并优化了添加变量表和添加设备的逻辑

Data/Entities/DbVariableTable.cs

@@ -12,6 +12,7 @@ public class DbVariableTable
 
     public string Name { get; set; }
 
+    public bool IsActive { get; set; }
     [SugarColumn(IsNullable = true)] public string? Description { get; set; }
 
     [SugarColumn(ColumnDataType = "varchar(20)", SqlParameterDbType = typeof(EnumToStringConvert))]