Summary:
This diff adds server side logging for all log levels in development (some levels sampled)
There are two new mobile analytic event pipelines (that pipe to scuba table)
- rn_dev_logs ([pigeon](https://our.intern.facebook.com/intern/marauder/event/?name=rn_dev_logs) [scuba](https://fburl.com/scuba/pqxl6mf5))
- rn_dev_logs_sampled ([pigeon](https://our.intern.facebook.com/intern/marauder/event/?name=rn_dev_logs_sampled) [scuba](https://fburl.com/scuba/oqz6b5x3))
Notes:
- All React Native logs from JS and Native on iOS go through this path to be printed to the console, so everything will be caputured even though native errors/warnings do not necessarily show a red/yellow box
- All errors and warnings are logged
- Log level info is sampled
Reviewed By: sammy-SC
Differential Revision: D17789494
fbshipit-source-id: dea6359237dbd91f267949f5185a0c79bb4083b8