[dbm] add service from integration configuration to dbm event payload

[lu-zhengda]

What does this PR do?

This PR adds service configured in integration init_config or instance config to the dbm events payload, including database_monitoring_query_sample, database_monitoring_query_activity and database_monitoring_query_metrics. The configured service will be converted to tag service:<SERVICE> and added to query metrics and query samples/explain plans.

Motivation

https://datadoghq.atlassian.net/browse/DBMON-4671

Additional Notes

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Changelog entries must be created for modifications to shipped code
• Add the qa/skip-qa label if the PR doesn't need to be tested during QA.
• If you need to backport this PR to another branch, you can add the backport/<branch-name> label to the PR and it will automatically open a backport PR once this one is merged

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.17%. Comparing base (dad9502) to head (eb8dfb9).
Report is 5 commits behind head on master.

Additional details and impacted files

Flag	Coverage Δ
activemq	?
cassandra	?
hive	?
hivemq	?
ignite	?
jboss_wildfly	?
kafka	?
mongo	93.27% <100.00%> (-0.24%)	⬇️
mysql	89.50% <100.00%> (-0.06%)	⬇️
postgres	93.29% <100.00%> (+3.96%)	⬆️
presto	?
solr	?
sqlserver	91.14% <100.00%> (+9.19%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.