Update docs/examples for harmony_service_lib v2.0.0 name change

[asjohnston-asf]

Several docs/examples still import harmony service lib as import harmony, which doesn't reflect last month's name change to import harmony_service_lib in release v2.0.0.

A quick look shows at least these two mentions that should be updated:

• https://github.com/nasa/harmony/blob/main/service-templates/sample_service.py#L15
• https://github.com/nasa/harmony/blob/main/docs/guides/adapting-new-services.md?plain=1#L83