Support configuring OTel SDK logger name and level

(Pull in changes from 10.0.3)

When traces can't be sent to the backend, verbose error messages are printed to stdout by the OpenTelemetry SDK (Python and C++). In some cases, users won't want to see that. We add an environment variable that allows the log level to be set.

Valid options are the Python log levels: critical, fatal, error, warning, info, debug, notset

The opentelemetry-python uses different logger names for the SDK error logs, depending on version. We use the known names by default.

As this may change in future, we add another env var to specify the names of the loggers to configure.

There is an open issue to add support for an OpenTelemetry-level environment variable. That may remove hte need for PyTango's own env vars. https://github.com/open-telemetry/opentelemetry-python/issues/1059