* schema/field:add UpdateDefault to numeric (#1718)
* schema/field:fix comment
* schema/field: change interface to self type with DefaultFunc/UpdateDefault
* schema/field: change interface to self type with DefaultFunc/UpdateDefault
* schema/field: change interface to self type with DefaultFunc/UpdateDefault
* schema/field: add support for setting update default funcs to numeric fields
Co-authored-by: godcong <jumbycc@163.com>