For most platforms except of NOVA a distinction between pager entrypoint
and pager activation is not needed, and only exists due to historical
reasons. Moreover, the pager thread's execution path is almost identical
between most platforms excluding NOVA, HW, and Fisco.OC. Therefore,
this commit unifies the pager loop for the other platforms, and removes
the pager activation class.
This allows us to see debug messages printed at the eary initialization
of init (before init is able to obtain the regular LOG session). This
will be reverted as soon as the initialziation of the non-core base
environment works.