Ports some of the custom PC port debugging code from Jak 1, such as the
entity debugger, Anim Tester X and part tester, to Jak 2 and gives the
PC menu code the same treatment Jak 1 received recently in #2216.
Some adjustments have been made to make things work in Jak 2 and some
stuff is still incomplete.
The majority of the default PC menu code has been left commented out in
preparation for @ManDude's plan to port the rest of the Jak 1 `pckernel`
features to Jak 2.
Also adds the code for `palace-scenes` to gsrc as that seems to have
been missed.
Hat Kid