utils_test: Enhance the run_autotest to support Client-Server model test.

Make host run server procee and copy the autotest to guest to run the client
process.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
tests: Introduce netperf into autotest in virttest.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>