Convert all code to use `logv2` headers and names

No logger/ headers. Use logv2/ headers instead.

MONGO_LOG_DEFAULT_COMPONENT => MONGO_LOGV2_DEFAULT_COMPONENT

Remove logger/log_version_util.h and its V1<=>V2 casting function wrappers.

Remove the legacy aliases in the logv2 headers.

Auditing should be the only place still using logger.

remove mentions of LogstreamBuilder.