refactor(*): Remove ProviderSynchronizerTypeWrapper and usage

[scottfrederick]

Following aaf1572, remove the ProviderSynchronizerTypeWrapper class and usage of it from all providers. This class was used to facilitate refreshing configuration via the /config-refresh controller, which was removed as part of the integration of Spring Cloud Config refresh and config server.

Also remove SCOPE_PROTOTYPE from @ConfigurationProperties beans, as these beans will get refreshed by Spring Cloud Config refresh when they are in the RefreshScope context.

[jkschneider]

@cfieber I think this gets us closer to being able to just use singletons and get rid of this prototype scoped weird anti-cyclic dependency thing.

[scottfrederick]

After these change, I only see one remaining use of SCOPE_PROTOTYPE in RetrofitConfig. I suspect that one can be deleted too, but I don't understand that config well enough to know for sure.

[scottfrederick]

@ezimanyi @cfieber Any feedback on this mass deletion of code?