TS 102 232-2 CR037 Add total recipients and update reference

Add MessagingIRI.total-Recipient-Count per requirement [E.1.5].

Fully qualify type names by prefixing with the module name
that they're imported from.

Remove trailing spaces and tabs.
Consistently use a 4 character tab instead of spaces.

Remove leading comment block for consistency with
the other 102 232 ASN.1.