* Removes retries from "pub get" and proxies its stdout output
* Fix issue where ErrorHandlingProcessManager does not forward "mode" parameter to backing ProcessManager's "start" method
* Make "pub get" use ProcessStartMode.inheritStdio instead of forwarding bytes to stdout and stderr
* Fix tests
* Remove unused env var
* Add back 'Running "flutter pub get"...' status log
* Fix indent
* Add Pub.test() constructor which lets tests mock stdio