fix: set service name in spring boot starter

[JamieDanielson]

Which problem is this PR solving?

• When using a non-classic API key... service.name is not properly set, resulting in traces ending up in wrong dataset. For example, with dataset=my-dataset and service.name=my-service, traces should show up in my-service dataset.

Short description of the changes

• set service.name in spring boot starter
• use process name instead of service name for default fallback
• don't throw on runtime exception
• update unit tests to assert ServiceName is properly used for dataset when sending
• add example spring app for manual testing
• fix some typos

TODO: handle classic key scenario for spring boot

[MikeGoldsmith]

Looking good. I'd recommend moving the removal of the bin dir and maybe the spelling changes into separate PRs so help keep each change concise.

[JamieDanielson]

closing as this is now being split into two PRs

• maint: remove and gitignore bin #316
• fix: set service name in spring boot starter #317