Modernize some CMake macros (Increases minimum required CMake version to 3.5)

[SunBlack]

This is a preparation for another change, which I didn't got ready today. But I think it's already enough for a PR.

//Edit: Typical error source: Using to modern CMake commands. PCL now requires CMake 3.5, because cmake_parse_arguments was new in CMake core with CMake 3.5. Wanted already to use PARSE_ARGV N, but this was introduced in 3.7, so had to use old way.
//Edit2: We could keep CMake 3.1 compatibility by calling include(CMakeParseArguments) before. As far as I see we used cmake_parse_arguments already before this changes, but we didn't included module, so CMake script was already broken for 3.4 and below xD

[SergioRAgostinho]

Don't forget to update these documentations files
https://github.com/PointCloudLibrary/pcl/pull/2605/files

[SergioRAgostinho]

When all is reviewed, I propose to squash the "fixup" commit df5b630 onto the original commit which generated that particular line.

[SunBlack]

How you want to squash with master? The fixup fixes something which is already merged into master.

[SergioRAgostinho]

Ignore what I said then 😅 I reviewed the PR per commit and thought it was something added on some previous commit.

[SergioRAgostinho]

Heads up: I'm unable to successfully configure CMake on my OSX environment after this PR. Need to figure out what is different between me and the CI.

Here's a really shortened version of the error log

CMake Error at cmake/pcl_targets.cmake:297 (install):
  install TARGETS given no RUNTIME DESTINATION for executable target
  "pcl_fs_face_detector".
Call Stack (most recent call first):
  apps/CMakeLists.txt:70 (PCL_ADD_EXECUTABLE)


CMake Error at cmake/pcl_targets.cmake:297 (install):
  install TARGETS given no RUNTIME DESTINATION for executable target
  "pcl_manual_registration".
Call Stack (most recent call first):
  apps/CMakeLists.txt:80 (PCL_ADD_EXECUTABLE)

It's being very clear about the reason. I'll dig into it to better understand what changed.