[fcformat] Add support for builtin formats

[fcformat] Add support for builtin formats

The '%{=unparse}' format expands to the FcNameUnparse() result on the
pattern.  Need to add '%{=verbose}' for FcPatternPrint() output but
need to change that function to output to a string first.

Also added the '%{=fclist}' and '%{=fcmatch}' which format like the
default format of fc-list and fc-match respectively.