Get rid of the duplication by rolling (almost) every test into a loop.
We now iterate over an array containing at least the name and list of sources.
To account for some differences between individual tests, we allow an
optional third array consisting of a dictionary for extra arguments.
In particular we ensure that the `test()` target now always depends on
the test binary, so that it will get properly rebuilt on changes to
the sources.
Note, that we're resorting in a separate commit, to ease reviewing.
Signed-off-by: Evangelos Ribeiro Tzaras <devrtz@fortysixandtwo.eu>
Part-of: <https://gitlab.gnome.org/GNOME/calls/-/merge_requests/798>
93a5c1911d