Use OpenTelemetry Semantic Conventions

[satabin]

This is an attempt at #1127 and an opportunity to align the existing traces with the ones defined in semantic conventions.

The current PR:

• improves existing spans by adding as many semantic convention attributes as possible
• includes available details in attributes in case we receive a PostgresErrorException
• creates client spans with custom finalizer to implement the above point
• records the operation duration on each exchange, adding as many attributes as possible

There currently are some limitations with this implementation:

• we do not have direct access to low-cardinality query summary, or I did not find how to get access to it
• span names are still the same generic names as before (e.g. query or execute)
• database name or query operation is not easily available on a query and is not added to the attributes
  • if there is a way to get these pieces of information easily that would be great, maybe I missed something
• this PR does not add the metrics which are still in development (e.g. the db.client.response.returned_rows or connection pool metrics are not added)
  • this could be added in a follow-up PR maybe
• it breaks the source and binary compatibility as the Histogram has to be propagated, I think it is not an issue, correct me if I'm wrong.