[exporter/clickhouse] Add client info for identifying exporter in system.query_log

[SpencerTorres]

Description:
(reopen from #34915)

This change will include information about the collector version and OS/Arch for every INSERT. Users can then track the origin of these queries in system.query_log. For an official build this will look something like otelcol/v0.114.0-lin-amd64.

This is implemented by setting client_info_product in the DSN. The underlying ClickHouse Go driver will then attach it upon connection. Users can already add their own version info in endpoint or connection_params, but this change will now safely set or append to that value with the binary's information.

Documentation:

• Added notes to README for client_product_info

Testing:

• Add/updated unit tests