xerrors: improve error message on parsing metasheet

[wenchy]

As metasheet @TABLEAU is defined as:

Sheet	OrderedMap	Mode
Item
Enum	MODE_ENUM_TYPE_MULTI

An error occured on parsing:

error[E2013]: invalid syntax of boolean value
工作簿: conf/Item.xlsx: failed to read book: conf/Item.xlsx: failed to parse metasheet: @TABLEAU: failed to parse metasheet 
工作表: @TABLEAU 
命名单元格位置: <no value>
命名单元格数据: <no value>
类型单元格位置: <no value>
类型单元格数据: <no value>|name:"OrderedMap" prop:{optional:true}
错误原因: 无法将 "MODE_ENUM_TYPE_MULTI" 解析为布尔类型, strconv.ParseBool: parsing "MODE_ENUM_TYPE_MULTI": invalid syntax

The problem is:

• error message has no cell position and cell data filled
• concrete error message mixes in workbook

[wenchy]

The error module should be set to ModuleConf.