resulttool/merge: Enable control TESTSERIES and extra configurations
Current QA team need to merge test result files from multiple sources.
Adding TESTSERIES configuration too early will have negative
implication to report and regression. Enable control to add TESTSERIES
when needed. Also enable adding EXECUTED_BY configuration when
needed.
Signed-off-by: Yeoh Ee Peng <ee.peng.yeoh@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
