* refactor: miniooni should be outside of the engine
This is part of https://github.com/ooni/probe/issues/1335. We also need
to think whether we wanna keep libminiooni and miniooni separated.
The previous use case for having a top-level libminiooni was that of
enabling others to integrate miniooni into other binaries.
This was usegul when studying internet censorship in Spain in May 2020.
I am wondering whether we should be keeping this complexity. I am not
sure about this and probably we should be killing it.
(In any case, reducing complexity is not the objective of this diff,
since I would like instead to move things around with minimal changes
and make sure we have a ~good repository organization here.)
* fix: import in libminiooni
* refactor: build miniooni from toplevel
Of course, also move the specific test checking whether we are
still able of building miniooni.
Part of https://github.com/ooni/probe/issues/1335
* build for current branch just to confirm
* fix: correct the path where linux/arm binary is
* okay, it works, we can remove the special rule
