[otelarrowreceiver, otelarrowexporter] Add internal/grpcutil package

[jmacd]

Description:
With utilities to encode and decode timeout in the syntax specified by gRPC.
This will be used by the otelarrow components to encode and decode timeout values.
In that sense, the new code could also be added into the pending internal/otelarrow package, see #33579

As this code is derived from gRPC-Go, some text is added in NOTICE according to the license. The code that this was derived from contained a TODO, which was largely addressed by eliminating very short timeouts from being encoded. This code will encode timeouts in milliseconds, seconds, hours, and days but it will not encode microsecond/nanosecond durations, these are rounded to 0m. The decoder will handle all durations that gRPC specifies, so that this logic can change in the future.

Link to tracking Issue: open-telemetry/otel-arrow#227

Testing: Adds basic tests.

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[jmacd]

This is part of open-telemetry/otel-arrow#227.

We were encouraged to move development of the otel-arrow components into this repository, but we need our PRs to merge for this to continue. :-)

[mwear]

LGTM. It'd be nice if a maintainer could double check the contents of NOTICE.

[jmacd]

@mwear I would be willing to move this module under internal/otelarrow as well. It's the same owners. It's meant for the two OTel-Arrow components to use, but it could be useful outside OTel-Arrow.

[jmacd]

It'd be nice if a maintainer could double check the contents of NOTICE.

For the record, the ASLv2 section 4(b) directs us to do this. There was already a NOTICE file concerning bits of gopsutil that were copied, and I just copied the pattern.

      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed
          as part of the Derivative Works; within the Source form or
          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
          wherever such third-party notices normally appear. The contents
          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.

[atoulme]

LGTM - my take is this is an internal package, it helps now, ok to get it in

[jmacd]

🥺 I think this could merge?

[jmacd]

Please merge this.

[jmacd]

I apologize for pushing this PR without apparently much cause. As we know, it is difficult to maintain multi-module PRs in this repository especially when introducing a new module. I could send a PR containing this PR combined with changes in otelarrowreceiver and one in otelarrowexporter. I could, but it would become harder to maintain and harder to review, so I've been waiting for this one to merge before sending more PRs. open-telemetry/otel-arrow#227

[evan-bradley]

Looks good to me overall, I don't have concerns with adding additional internal modules.

I'm not totally clear on the license requirements, but what's here seems sufficient to me. I'll merge this after the release is completed tomorrow if there aren't further comments.

[mx-psi]

@evan-bradley is this good to merge?