oe-build-perf-test: save test metadata in a separate file
The patch introduces a new metadata (.json or .xml) file in the output
directory. All test meta data, e.g. git revision information and tester
host information is now stored there. The JSON report format is slightly
changed as the metadata is not present in results.json anymore.
[YOCTO #10590]
Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
