Test prep for porting UserCreateTag to Go
These are test preparations for my !2911 (merged) MR.
This depends on !2953 (closed) the first 2 patches from it are here too. Once that's approved I can rebase this one.
There's only an improvement in test coverage here (past the first 2 patches). The main MR currently has these commits too, so once this is merged I can rebase and it'll be much easier to review.
See !2881 (merged) for the previous test prep
Edited by Ævar Arnfjörð Bjarmason