Add compliance checks for the X.509 version field

Add compliance checks for the X.509 version field

Check whether the X.509 version is in the range of valid version
values, and also checks whether the version is consistent with fields
new to those versions (such as X.509 v3 extensions).

X.690 section 11.5 states: "The encoding of a set value or a sequence
value shall not include an encoding for any component value which is
equal to its default value." However, enforcing version 1 (value 0) to
be absent reportedly caused some issues as recent as July 2020, so
accept version 1 even if it is explicitly encoded.

OK tb@ beck@