test/execution: fix go module paths

This is part of a gradual transition of platform/dev
to Go modules compatible package import paths.

It is just an ebuild and source reorganization, GOPATH
mode is still the default.

BUG=b:187795288
TEST=Local builds; CQ.

Cq-Depend: chromium:5401631
Change-Id: Idf6b1e8962dfc328107b7c50568fd867a3e4b96c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/5401804
Reviewed-by: Jaques Clapauch <jaquesc@google.com>
Tested-by: Adrian Ratiu <adrian.ratiu@collabora.corp-partner.google.com>
Commit-Queue: Adrian Ratiu <adrian.ratiu@collabora.corp-partner.google.com>
54 files changed