buffet: Add parsing of command instances from JSON

CommandInstance class can be created from a JSON object
with proper command and parameter value validation against
command definition schema.

BUG=chromium:396713
TEST=USE=buffet P2_TEST_FILTER="buffet::*" FEATURES=test emerge-link platform2

Change-Id: Iba4c807225552f6a9d8b33a0aa1fc451e75753a4
Reviewed-on: https://chromium-review.googlesource.com/211338
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
6 files changed
tree: 51ddf4c11e486e6def70de7bc03d95fff5b23496
  1. buffet/