Introduce sysputpage() to display large page size with human readable format.

Introduce sysputpage() to display large page size with human readable format.
Using UI units allows to fit larger numbers in columns.
Stop calling v_page_size - this is a value that doesn't change at runtime.
Renamed WINDOW *wnd to *wd to avoid conflict with global *wnd variable.
Use bit-shift to convert page size to byte.

PR:             246458
Submitted by:   ota@j.email.ne.jp
MFC after: 2 weeks
Differential Revision:  D24834