common: rename utils -> edencommon_utils
common: rename utils -> edencommon_utils

Summary:
Fixes https://github.com/facebookexperimental/edencommon/issues/3

`utils` is a bit too generic and Gentoo seems to be building edencommon into a shared library.

Reviewed By: chadaustin

Differential Revision: D38719753

fbshipit-source-id: fb46b6a7c9d3bcc3034765cb47e997a80c646b3d

facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman