Assert telemetry not accepted after shutdown

[fractalwrench]

Goal

Write test cases that check telemetry submitted after shutdown is not accepted. CloseableOpenTelemetryImplTest has made a start at this.

Partially addresses #69.

[bidetofevil]

I think this addresses #71

[bidetofevil]

Work here will include:

• Make the span and log exporters and processors not process or export telemetry post shutdown
• Make tracer and logger provider provide no-op implementations post shutdown
• Make tracers create no-op spans post shutdown
• Make loggers not emit any telemetry post shutdown
• Tests for all test scenarios