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The current dependency relationship in vtk is unclear and misleading.
This MR tries to rewrite them based on header files inclusion of headers
and source files in each module. Corner cases are considered and
modules are sorted in alphabetical order to facilitate future reference.
See details in my gitlab python based script project. In future we can continue
using this script to clean the VTK Dependency easily from
time to time.

Code extracted from:

    https://gitlab.kitware.com/third-party/proj.git

at commit 41bdf05361007f8c5186f3df9944d86bb273ed13 (for/vtk).

Add module.cmake, CMakeLists.txt, and other build system files.

The modular VTK build system is not yet mature.  The monolithic build
files had a lot of infrastructure.  The modular build files reproduce
much of the functionality but some features will need to be restored
later.  Document status and tasks in "TODO-Modularization.txt".

Co-Author: Marcus D. Hanwell <marcus.hanwell@kitware.com>
Co-Author: Chris Harris <chris.harris@kitware.com>
Co-Author: Brad King <brad.king@kitware.com>
Co-Author: Nikhil Shetty <nikhil.shetty@kitware.com>