Database OpenTelemetry specification conventions

[wdalmut]

We have to check that we are respecting OpenTelemetry specification for databases: https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/overview.md#semantic-conventions.md

[blumamir]

Link to the Semantic conventions for database client calls:
https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/trace/semantic_conventions/database.md