OpenTelemetry Go Launcher

[JamieDanielson]

As discussed briefly in CNCF Slack and in the Go SIG meeting, we would like to contribute a vendor-neutral launcher to streamline configuration of the Go SDK.

Please review the design document for the OpenTelemetry Go Launcher for further discussion. A branch (WIP) for further review of the code can be found in the Honeycomb fork of this repo.

Update: Opened PR 2592 for further discussion as requested.