[resultdb] Add db fields and indices for test results history api.
[resultdb] Add db fields and indices for test results history api.

R=chanli,nodir

Bug: 1074407
Change-Id: I880e81b144b9c878a9866d18d85206f000deeb88
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2347910
Commit-Queue: Roberto Carrillo <b31161e510fbb37f8f70fdcde11530d2bae88470@chromium.org>
Reviewed-by: Chan Li <332b6c56634d0f63001046c664a2370006a02420@chromium.org>
Reviewed-by: Nodir Turakulov <ef4933a197ef7b4b3f55f1bec4942aead3637a2a@chromium.org>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go