The tests e2e need the mail template to
send the invitation to the user.
We are now caching the mail template instead
of using a artifact, thanks to that we can
build only the mail template if the cache is
invalidated, so we save time and resources.
The linter in the CI was checking only the
impress directory. We were passing near some lint
issues. Now the linter checks the whole backend
directory.
We want to be able to share a document with a person even if this person
does not have an account in impress yet.
This code is ported from https://github.com/numerique-gouv/people.
