Output: Get the output as close as possible to the Canonical Event Log format

[bgartzi]

The TCG defines the Canonical Event Log Format.

There are some issues, as for example recnum prediction. However, it would be preferable if we could get the output of the predict_pcr functions as close as possible to the defined format.

This will probably require extending the Pcr and Parts structs on lib/src/lib.rs, and modifying pieces of code so as to fill the new fields correctly.