SWATCH-2963: Count Splunk transmission failures in Quarkus apps

[awood]

Jira issue: SWATCH-2963

Description

We have a custom Splunk error callback that increments a counter when failures
occur during message transmission. Unfortunately, that callback was only being
applied to swatch-producer-aws. This PR applies the callback to all Quarkus
applications.

Testing

Steps

1. On main:

   ./gradlew :swatch-contracts:quarkusDev &
   http :9000/metrics | grep splunk
   

2. Repeat on this branch

3. Deploy this branch again like so:

   ENABLE_SPLUNK_HEC=true \
   SPLUNK_HEC_URL=https://localhost:8088 \
   SPLUNK_HEC_TOKEN=foobar \
   ./gradlew :swatch-contracts:quarkusDev &
   sleep 20
   http :9000/metrics | grep splunk
   

   The non-existent URL will result in a bunch of message failures (although
   you will need to wait a bit for them to register). The counter will get
   incremented.

Verification

1. On main you will not see the metric listed. On this branch it'll be there.
2. For the last step, the counter will be non-zero.

[awood]

/retest

[awood]

/retest

[awood]

/retest

[awood]

/retest

[TrayvonMcKnight]

/retest