CNCF OpenTelemetry with optional gzip compression

[darach]

Pull request

This is a manual patch / cherrypick of daksh's contribution for CNCF OpenTelemetry with optional gzip
compression support originated in the stalled #1818 branch. Recent changes in external dependencies
and to tremor mean this work is now mergeable.

@dak-x Let me know if you'd prefer to resolve #1818 or we can go ahead with this branch which basically
avoids most of the merge pain!

Description

Adds compression support to the otel connectors:

  define connector otel_client from otel_client
  with
    config = {
      "url": "127.0.0.1:4317",
      "compression": "gzip", # This is new from Daksh's contribution
    },
    reconnect = {
      "retry": {
        "interval_ms": 100,
        "growth_rate": 2,
        "max_retries": 3,
      }
    }
  end;

Related

Supercedes #1818

Checklist

• The RFC, if required, has been submitted and approved
• Any user-facing impact of the changes is reflected in docs.tremor.rs
• The code is tested
• Use of unsafe code is reasoned about in a comment
• Update CHANGELOG.md appropriately, recording any changes, bug fixes, or other observable changes in behavior
• The performance impact of the change is measured (see below)

Performance

Compression is a tradeoff of network bandwidth utilisation and cpu utilization. Unless explicitly configured
compression is disabled by default.

[dak-x]

I believe we would need to spend effort in upgrading our tonic in termor-otelapis. Tonic 0.6 and 0.7 both are being consumed due to a dependency on googapis. I remember @mfelsche mentioning a solution in this regard (couldn't find it).

[darach]

Yes. Its a fairly deep set of changes given that we need a common tonic/prost across all gRPC or protocol buffer
based connectors. Additionally the GCP and Otel specifications have revv'd resulting in some other changes to
underlying deps. I have most of the changes in progress with a preview/draft branch hopefully soon!

[Licenser]

closing this as its part of the huge otel update coming down the line