tests: qemucaps: Make JSON output identical to python's 'json.dump' method

tests: qemucaps: Make JSON output identical to python's 'json.dump' method

YAJL formats empty objects and arrays in a weird way:

 {
   "emptyarray": [

   ],
   "emptyobject": {

   }
 }

We want to use empty lines to separate commands and replies as well as
be compatible with python's 'json.dump' method, thus we drop any
whitespace between array/object braces.

Adjust the two formatters which are used for capabilities and fix all
output files.

Note that the code is duplicated in qemucapabilitiesnumbering.c and
qemucapsprobemock.c, but later patches will replace
qemucapabilitiesnumbering.c by a python tool.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>