Fix exception thrown when LoggerProvider not configured

[lzchen]

If a LoggerHandler is instantiated without an SDK LoggerProvider, an exception is thrown here since NoOpLogger does not have the resource attribute.

Repro:

...
# do not set SDK Loggerprovider

handler = LoggingHandler(level=logging.NOTSET)
logging.getLogger().addHandler(handler)
logging.info("Jackdaws love my big sphinx of quartz.")
...

[srikanthccv]

Some minor comments

[srikanthccv]

Thank you