Migrate to use GNUInstallDirs

Proper install DIRS paths using the canonical forms
Install cmake finder in a multi-arch compatible place
FindSimbody.cmake aware of multiarch and install to proper place

Fix debian metadata to keep in sync with latest improvements
Rename Simbody cmake finder
USe CMAKE_INSTALL_DOCDIR for documentation
Use CMAKE_INSTALL_DOCDIR as destinatin for docs
Move to install binaries in FULL_BINDIR
Move simbody-visualizer app to proper package
Move simbody-visualizer app to proper package
Fix path with documentation