Gh-3187: Add Open Telemetry proof of concept

[tb06904]

Adds a basic implementation of Open Telemetry that will record Spans across executions of Operations/OperationChains. Can be toggled on via a otelActive option in the graphConfig.json (off by default). Hopefully is a useful start point to be expanded on if required.

Is difficult one to demonstrate via unit testing but been manually tested to ensure Spans look useful with relevant data via a Jaeger UI. Uses the auto configure feature of Open Telemetry so can be easily configured where and how to export data to via environment variables e.g.

• OTEL_SERVICE_NAME=gaffer-rest - sets the service name to gaffer-rest
• OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=http://jaeger:4317 - sets the endpoint to export traces to e.g. Jaeger
• OTEL_TRACES_EXPORTER=console - sets the exporter to console rather than the default of OTEL (needs to be OTEL to work with Jaeger).

Related issue

• Resolve #3187

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 72.50000% with 11 lines in your changes are missing coverage. Please review.

Project coverage is 66.70%. Comparing base (1836a6f) to head (a8e9fde).

Files	Patch %	Lines
...a/uk/gov/gchq/gaffer/commonutil/otel/OtelUtil.java	0.00%	10 Missing :warning:
...ain/java/uk/gov/gchq/gaffer/graph/GraphConfig.java	87.50%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #3189 +/- ## ========================================== Coverage 66.70% 66.70% + Complexity 2559 2558 -1 ========================================== Files 907 908 +1 Lines 29076 29113 +37 Branches 3241 3243 +2 ========================================== + Hits 19396 19421 +25 - Misses 8248 8259 +11 - Partials 1432 1433 +1 ```

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