Introduce PayloadVersion struct for version information.

This new little struct encapsulates the version information (major and
minor version numbers) and the zlib fingerprint information. Now,
instead of querying throughout if the version number is certain value,
we ask the PayloadVersion struct whether certain operation is allowed in
that version or not. This moves the logic of what's supported and
what's not to a single place and eliminates the need to pass several
booleans to the helper functions.

Bug: None
TEST=Unittest still pass.

Change-Id: Iaa6e7bc032db6479fdeab72255d7062fca1c07e5