PMM-14799 Add RTA telemetry metrics

[maxkondr]

https://jira.percona.com/browse/PMM-14799

percona/pmm#5081

[JNKPercona]

Server docker: perconalab/pmm-server-fb:PR-4243-379fa00
Client docker: perconalab/pmm-client-fb:PR-4243-379fa00
Watchtower docker: perconalab/pmm-watchtower-fb:PR-4243-379fa00
Client tarball: https://s3.us-east-2.amazonaws.com/pmm-build-cache/PR-BUILDS/pmm-client/pmm-client-PR-4243-379fa00.tar.gz
Staging instance: https://pmm.cd.percona.com/job/pmm3-aws-staging-start/parambuild/?DOCKER_VERSION=perconalab/pmm-server-fb:PR-4243-379fa00&CLIENT_VERSION=https://s3.us-east-2.amazonaws.com/pmm-build-cache/PR-BUILDS/pmm-client/pmm-client-PR-4243-379fa00.tar.gz

[JNKPercona]

API tests have succeded: https://pmm.cd.percona.com/job/pmm3-api-tests/5372/

[JNKPercona]

Server docker: perconalab/pmm-server-fb:PR-4243-9796614
Client docker: perconalab/pmm-client-fb:PR-4243-9796614
Watchtower docker: perconalab/pmm-watchtower-fb:PR-4243-9796614
Client tarball: https://s3.us-east-2.amazonaws.com/pmm-build-cache/PR-BUILDS/pmm-client/pmm-client-PR-4243-9796614.tar.gz
Staging instance: https://pmm.cd.percona.com/job/pmm3-aws-staging-start/parambuild/?DOCKER_VERSION=perconalab/pmm-server-fb:PR-4243-9796614&CLIENT_VERSION=https://s3.us-east-2.amazonaws.com/pmm-build-cache/PR-BUILDS/pmm-client/pmm-client-PR-4243-9796614.tar.gz

[JNKPercona]

API tests have succeded: https://pmm.cd.percona.com/job/pmm3-api-tests/5377/