Add Helidon Metrics integration with OCI

[klustria]

The change includes the following:

1. Port of PR Add Helidon Metrics integration with OCI #4003 that adds the Helidon Metrics to OCI integration
2. Port of PR Fixed race condition in the OCI Metrics integration test between retrieval of metrics from registry and asserting that from expected results #4897 that fixes race condition in the unit test
3. Adjust code to deal with MP metrics API changes
4. Change endpoint to the ingestion endpoint when posting the metrics as this is not handled anymore by the OCI SDK integration due to changes in the OCI Java SDK v3.
5. Change MonitoringClient.class to Monitoring.class for mocking using Mockito in the unit test as the OCI Java SDK v3 converted some of the methods in MonitoringClient as Final making them difficult to mock.
6. Trim the OCI Metadata value which contains the metric description if the value exceeds 256 characters, otherwise it will fail.
7. OCI Monitoring service only allows a maximum of 50 metrics per posting, hence additional configuration parameters were added to control sending metrics in batches. The configuration parameters are: a. batchSize - Maximum no. of metrics to send in a batch. Defaults to 50 which is what OCI allows b. batchDelay - Interval between batch posting For example if there are 51 metrics and batchSize is set to 25 and batchDelay to 5 seconds, the Helidon metric integration module will divide the posting to 3 batches sending 25 metrics on the 1st and 2nd batches and 1 metric on the 3rd batch with 5 seconds interval between batch posting.
8. Refactor OciMetricsCdiExtension to add a new bean (OciMetricsBean) to handle the Observer method which will inject Monitoring. Previous code of OciMetricsCdiExtension cannot independently handle instantiation of Monitoring client via CDI.
9. Add unit tests to verify batch posting feature and the use of ingestion endpoint.

[tjquinno]

A few notes.