crosperf: introduce option "compress_results" for result directory

Perf data and report file can occupy large disk space when we copy and
store them in the crosperf results directory. This patch introduces a
new field for crosperf so that we create a tarball for it to save space.

By default compress_result is set to True.

BUG=chromium:1079048
TEST=Passed unittest, tested with simple examples.

Change-Id: I70db6f3f70dc33bacfccd8833a4327c494b4d6b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2212432
Reviewed-by: George Burgess <gbiv@chromium.org>
Commit-Queue: Zhizhou Yang <zhizhouy@google.com>
Tested-by: Zhizhou Yang <zhizhouy@google.com>
8 files changed