fbpreprocessor: Feedback report files preprocessor

fbpreprocessord is a daemon that preprocesses files such as WiFi firmware debug dumps so they can be added to feedback reports.

Design documents

• General architecture of the firmware debug dump feature: go/cros-wifi-fw-dumps-architecture
• fbpreprocessord design: go/cros-fbpreprocessord-dd
• Design to add support for BT firmware debug dumps: go/cros-bt-fw-dump-fbreport