Reduce log level for query logs

[denniskniep]

All queries executed are logged with "Info" level:

kniepdennis-neo4j-datasource-grafana-1 | logger=plugin.kniepdennis-neo4j-datasource t=2023-07-28T09:26:20.46+0000 lvl=info msg="Execute Cypher Query: 'Match(m:Movie) return m.title'" DATASOURCE_UID=229051cf-d4fc-4aef-b9c0-dbade6e69339

This is an issue both from the storage (it may log a lot of lines) and security perspective (it may log secrets encoded in queries). Use the "debug" level instead.

Review generally all the loglevels