The source project of this merge request has been removed.
tests: add the valgrind suppression file from the "common" module
Other gstreamer repositories have their own valgrind suppression file directly in the repository.
Add a suppression file to the core gstreamer repository too, this makes it easier to use it with gst-build which does not check out the common module.
See !62
This is also a little step towards the removal of the common submodule.
NOTE: the added file is the latest version from the "common" repository but it has been renamed from gst.supp to gstreamer.supp for symmetry with the suppression files in the other repositories.