Add Grafana dashboard for monitoring OPEA application scaling in k8s (#…

…541)

* Add helper script to create/update Grafana dashboards

Signed-off-by: Eero Tamminen <[email protected]>

* Add Grafana dashboard for OPEA application scaling metrics

Signed-off-by: Eero Tamminen <[email protected]>

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

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Signed-off-by: Eero Tamminen <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>