PMM: Add value to change log level

[TomKeur]

Hi,

Great product! I've been using using the Percona Operator for MySQL based on Percona XtraDB Cluster in combination with PMM, this is my configuration.

pmm:
  enabled: true
  serverHost: monitoring-service

This is all running great, the only thing I'm noticing, the pmm-client container is generarting a lot of (info), logs.
For example:

time="2024-03-12T06:55:00.052+00:00" level=info msg="Sending 48 buckets." agentID=/agent_id/xxx component=agent-builtin type=qan_mysql_perf
schema_agent

It should be great if there a way we can change the loglevel, for example with:

pmm:
  enabled: true
  serverHost: monitoring-service
  log:
    level: error