This change adds a core_generate_all make target.
It installs the required tools and runs generate on the complete project.
`golang/mock` is no longer maintained and a fork is available
from the Uber folks. So the latter is used as tool.
All the mock files have been regenerated and are part of the PR.
The obsolete `tools` directory has been removed,
as all the tools are now part of specific make targets.
Co-authored-by: Silvan <silvan.reusser@gmail.com>