SWATCH-2303: Add a metric to swatch-producer-azure for metered usage

[Sgitario]

Jira issue: SWATCH-2303

Description

When usage is processed by swatch-producer-azure, it should increment a counter named "swatch_producer_metered_total" with the amount in metric units, having labels:

product (swatch product tag)
metric_id (metric ID)
billing_provider
status (failed or succeeded)
What about retry: we only care about the final state after Azure returns

Testing

Added junit test to ensure the metric is populated.

Manual verification

1. podman-compose up
2. start azure service:

SERVER_PORT=8001 QUARKUS_MANAGEMENT_PORT=9001 ./gradlew :swatch-producer-azure:quarkusDev

3. send message to topic "platform.rhsm-subscriptions.billable-usage-hourly-aggregate":

{"windowTimestamp":"2023-12-21T01:10:28Z","aggregateId": "e81bc918-6434-4a58-9192-8a8dd73ec8fb","aggregateKey": {"orgId": "org123","billingProvider": "azure","metricId": "Cores","productId": "rosa"}}

Note that this message is expected to fail at usage context lookup

4. verification:
   The metrics from the swatch producer azure service should contain the new metric:

curl http://localhost:9001/metrics  | grep swatch_
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0# TYPE swatch_producer_metered counter
# HELP swatch_producer_metered  
swatch_producer_metered_total{billing_provider="azure",error_code="usage_context_lookup",metric_id="Cores",product="rosa",status="failed"} 0.0
# TYPE swatch_azure_marketplace_batch_rejected counter
# HELP swatch_azure_marketplace_batch_rejected  
swatch_azure_marketplace_batch_rejected_total 0.0
# TYPE swatch_azure_marketplace_batch_accepted counter
# HELP swatch_azure_marketplace_batch_accepted  
swatch_azure_marketplace_batch_accepted_total 0.0

Note that the new metric is "swatch_producer_metered_total".