ref-filter: add %(rest) atom

ref-filter: add %(rest) atom

%(rest) is a atom used for cat-file batch mode, which can split
the input lines at the first whitespace boundary, all characters
before that whitespace are considered to be the object name;
characters after that first run of whitespace (i.e., the "rest"
of the line) are output in place of the %(rest) atom.

In order to let "cat-file --batch=%(rest)" use the ref-filter
interface, add %(rest) atom for ref-filter.

Introduce the reject_atom() to reject the atom %(rest) for
"git for-each-ref", "git branch", "git tag" and "git verify-tag".

Reviewed-by: Jacob Keller <jacob.keller@gmail.com>
Suggected-by: Jacob Keller <jacob.keller@gmail.com>
Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Hariom Verma <hariom18599@gmail.com>
Signed-off-by: ZheNing Hu <adlternative@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>