FI-3023: Add default env vars and documentation to validator dockerfile

[dehall]

Summary

In anticipation of inferno-resource-validator v1.0.59, this sets two new environment variable defaults in the docker image:

• SESSION_CACHE_IMPLEMENTATION=PassiveExpiringSessionCache
  • Previously the PassiveExpiringSessionCache was the only implementation but then a different session cache was added, without support for a "never expire" value
• SESSION_CACHE_DURATION=-1
  • Sets the session cache to "never expire". This is set on every test kit currently, but it makes more sense to keep these defaults here so we don't have to update dozens of test kits if things change behind the scenes like this.

And adds documentation explaining these variables plus the recommended update sequence when there's a new version.

Note I added the = to the other env var lines because I got warnings like this from the build otherwise:

 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 20)

Testing Guidance

To build the image for 1.0.59 and load it locally without pushing to docker hub, run:

docker buildx build --platform linux/arm64 --build-arg "PROJECT_VERSION=1.0.59" --tag "infernocommunity/inferno-resource-validator:1.0.59" --load .

(this is the same as the build script in the same folder, but with --load instead of --push and only building for arm64)

After that, this can be tested directly against g10 by running this branch: onc-healthit/onc-certification-g10-test-kit#592

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.05%. Comparing base (88bc16c) to head (420661b).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #562   +/-   ##
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  Coverage   84.05%   84.05%           
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  Files         262      262           
  Lines       11415    11415           
  Branches     1256     1256           
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  Hits         9595     9595           
  Misses       1810     1810           
  Partials       10       10           

Flag	Coverage Δ
backend	92.17% <ø> (ø)
frontend	79.31% <ø> (ø)

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• Flaky Tests Detection - Detect and resolve failed and flaky tests

[dehall]

Update: validator-wrapper 1.0.59 was just now released upstream so marking this as draft while I test that out

[dehall]

Looks like no additional changes needed for 1.0.59 so moving forward with that