dump_page_queue(): fix output

* Determine the cache type per page instead of printing the first page's
  cache type for all pages.
* Use vm_cache_type_to_string().
X86PagingStructuresPAE: clear fVirtualPageDirs in constructor

... not just the first element. Fixes a crash in X86VMTranslationMapPAE
destructor when running out of memory when initializing the map.
arch_vm_translation_map_early_map(): Fix debug output
X86VMTranslationMapPAE::Map(): More info in assert
X86VMTranslationMapPAE: Add some ktracing for page (un)mapping
When switching to PAE don't copy not needed PTEs

Now we check whether the virtual address corresponding to the PTE lies
in an allocated virtual address range. This fixes a cause of #8345:
The assertion would trigger when such an entry was encountered. There
might be other causes that trigger the same assertion, though.