Add a script to parse an block-based ota package

The script prints the meta info, new/patch data size. It also simulates
the transfer commands and calculates amount of I/O as well as cache
needed.

We can add the more options to parse system/vendor.map so that we can
analyze the location change of files.

Bug: 31514709
Test: parse a bullhead incremental/full ota.
Change-Id: I70ed4f4c15e595b1851109e9799d44ac4e815c16