Add command line action sequencing.

Supported actions:
* .. scan <process> ..
* .. scan-all ..
* .. import <infile> ..
* .. export <infile> ..
* .. comp <thresh> <outfile> ..
Test: manual
Bug: 31961946

Change-Id: I08753f31294ac5f30f6bcddeabef12d138e7e8e6