Add tests around the loader-metadata chart

swh/templates/loader-metadata/keda-autoscaling.yaml

swh/templates/loader-metadata/keda-secrets.yaml

swh/tests/loader_metadata_configmap_test.yaml

swh/tests/loader_metadata_configmap_utils_test.yaml

swh/tests/loader_metadata_deployment_test.yaml

swh/tests/loader_metadata_global_test.yaml

swh/tests/loader_metadata_keda_autoscaling_test.yaml

swh/tests/loader_metadata_keda_secrets_test.yaml

swh/tests/values/loader-metadata.yaml

swh/values.yaml

swh/values/staging.yaml