ASSERT_PTR() and friends in assert-fundamental.h make use of assert()
and assert_se() which when not building for sd-boot are defined in
assert-util.h. Because assert() from glibc is only overridden in
assert-util.h, the macros in assert-fundamental.h still end up using
the glibc assert.
Let's fix this by moving the required macros and related logic to
assert-fundamental.h.
Various functions in log.h are only used by asserts, and there's
enough assertion related stuff in macro.h to justify a separate header
which also makes it easier to avoid circular dependencies.
Let's introduce assert-util.h and an accompanying fundamental header
and move all the assertion related stuff over there. PROJECT_FILE is
moved over to macro.h.
