This adds a version to the deply data format, assuming that if
there is no version then it is 0. Also extends all loaders so that
it can specify a required version, with the goal that most users
are fine with old versions, but if you need more recent we have
a (costly) conversion process to upgrade (will be added later).
The library and the flatpak list/info commands require the most
current version for full info, all other users can use any version.
Also, as part of this we now pass the ref to flatpak_load_deploy_data()
as this will be needed later for the backwards compat support.
Closes: #2409
Approved by: alexlarsson
Alexander Larsson
9a37475e76