build target destinations inconsistencies for migrated apps

[macmpi]

Newly migrated applications do not install components in consistent manner with previous utils repo apps.
For instance looking at dtmerge:
${CMAKE_INSTALL_MANDIR} (which may usually translate into share/man/man1 ) vs explicit man/man1 for dtoverlay & al
(same explicit for bin)

Would help to have consistency across utils repo apps (ideally stick to ${CMAKE_INSTALL_BINDIR} / ${CMAKE_INSTALL_MANDIR}): thanks for consideration.
@pelwell @XECDesign