TRT-635: Refine HarmonyAdapter.reformat method.

[owenlittlejohns]

Description

This PR tidies up the HarmonyAdapter.reformat method. The outputs of this service are only GeoTIFF or netCDF4. Although, there is the potential for HGA to be chained with other things that can request a different format. As HGA doesn't know if it is the last step in the chain, we shouldn't raise an exception.

Jira Issue ID

TRT-635

Local Test Steps

Check unit tests run: ./bin/build-image && ./bin/build-test && ./bin/run-test

Check regression tests run (updated ones):

• Use the branch from this PR against Harmony.
• Make sure HGA is in your Harmony .env: LOCALLY_DEPLOYED_SERVICES=harmony-gdal-adapter.
• Start Harmony (./bin/bootstrap-harmony in the Harmony repository)
• Cut over to the regression test repo.
• Pull the code from this branch
• Run the notebook in a browser, changing harmony_host_url='http://localhost:3000'. All tests should pass.

PR Acceptance Checklist

• Jira ticket acceptance criteria met.
• version.txt and CHANGELOG.md updated if any service code is changed.
• Tests added/updated and passing.
• Documentation updated (if needed).

[flamingbear]

This didn't seem like a patch at first, but makes sense on closer examination. I verified all of the test instructions for the unit and regression tests. always good to 🪓 code