[Header] Lack of verifiable properties

[hyunsooda]

Is your request related to a problem? Please describe.
As the governance values are not parts of a header, these values must be referred to by nodes that service governance namespace. The problem is, here, the values are not verifiable as is. Moreover, as the governance values affect on consensus and policy (block generation), abstract one such as transaction root seems provided together.

Describe the solution you'd like
it can be simply verified if they are interleaved into the process of hash calculation of the header.

Describe alternatives you've considered

Additional context
Header size may be a hurdle in incorporating those values, so a compressed expression may be required.

cc. @blukat29, @aidan-kwon

[exalate-issue-sync]

Exalate commented: Issue Created by: hyunsooda