We want to move platform code to "shared/nm-platform". However, platform
code uses the logging infrastructure from the daemon, there is thus
an odd circular dependency.
Solve that by moving the "src/nm-logging.[hc]" to a new helper library
in "shared/nm-log-core".
NetworkManager core is huge. We should try to split out
parts that are independent.
Platform code is already mostly independent. But due to having it
under "src/", there is no strict separation/layering which determines
the parts that can work independently. So, while the code is mostly
independent (in practice), that is not obvious from looking at the
source tree. It thus still contributes to cognitive load.
Add a shared library "shared/nm-platform", which should have no
dependencies on libnm-core or NetworkManager core.
In a first step, move the netlink code there. More should follow.