Add support for subscription services

[cyril-L]

I am posting this to get a review before actually passing homologation (most of the test cases get the expected result though).

I will do the homologation process after the review, to ensure the merged code actually pass. Could you wait for my confirmation before the merge?

[cyril-L]

The code have been homologated, I am moving test cases to homologation.md.

[cyril-L]

Should be good now!

[philpep]

Merged, thanks a lot!