Do not save \origin when \save_transient_properties is false (#9958)

Do not save \origin when \save_transient_properties is false (#9958)

\origin is a transient property in the sense that in a collaborative context
each co-author is going to have a different value for it. Moreover, \save_origin
is a global (lyxrc) setting that cannot yet be deactivated for a single file,
but one author's setting is going to impact other authors, even those who have
set save_origin=false.

There is only one location where lyxrc.save_origin produces an effect, modified
by this patch. With this patch, everything happens as if lyxrc.save_origin was
false whenever save_transient_properties=false.

This is not a file format change. When a file has
save_transient_properties=false but an origin is set (for instance a file
produced before this patch) then the origin produces its effect before the file
is saved. This produces the same effect as if the user decided to disable
save_origin between two sessions.