Wherever a struct/union/alternate/command/event member with NAME: TYPE
form is accepted, desugar it to a NAME: { 'type': TYPE } form.

This will allow to add new member details, such as 'if' in the
following patch to introduce conditionals, or 'default' for default
values etc.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20181213123724.4866-13-marcandre.lureau@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>