Summary

ClientInfo is appended per-query, but it can only be set upon connection.

This PR allows users to append to it per-query. The original ClientInfo from the initial connection is unaffected, it's append-only.

Changes:

• Add WithClientInfo function for usage with clickhouse.Context
• Made Comment public on ClientInfo so users can append to it in their clickhouse.Options config
• Updated TCP and HTTP usage. ClientInfo is merged from connection options and query options.
• Updated unit + integration tests

Usage

// This data will be appended to the existing ClientInfo from clickhouse.Options
queryCtx := clickhouse.Context(ctx, clickhouse.WithClientInfo(clickhouse.ClientInfo{
	Products: []struct {
		Name    string
		Version string
	}{
		{ Name:    "ctxProduct", Version: "1.2.3" },
	},
	Comment: []string{"ctxComment"},
}))

// The system.query_log table will include the additional ClientInfo from the queryCtx
row := conn.QueryRow(queryCtx, "SELECT 1")

Checklist

• Unit and integration tests covering the common scenarios were added