Feature Request: Remove Truncation from Args When Logging

In `func logQueryArgs(args []interface{})` it looks like `pgx` deliberately truncates long args. We need to be able to use the full args to debug our queries in staging.

Can we remove this truncation completely or add a config param that would allow full args to be logger?

I'm happy to make the change in a pr. Just let me know which you prefer.

Start at the mentioned `logQueryArgs(args []interface{})` entry point and trace how its output is sent to the logger. Determine whether the intended behavior is always-full arguments or an opt-in configuration, then verify that the selected behavior is covered by the existing logging tests, if present.

Written by the indexing model from the issue text.