Rename Builder to ThingBeingBuiltBuilder

[cijothomas]

Example: https://github.com/open-telemetry/opentelemetry-rust/blob/main/opentelemetry-sdk/src/logs/log_emitter.rs#L182 where just Builder is used. Except for provider, every other place uses the name "ThingbeingBuiltBuilder" pattern.

Opening to see if there are suggestions/feedback on this. Otherwise, we should rename Builder to LoggerProviderBuilder and do this consistently across.

[lalitb]

I prefer the name LoggerProviderBuilder; in general, names should be more descriptive and self-explanatory.