* package.xml: Activate dependency on hpp-fcl

hpp-fcl v1.8.1 is now available for ROS Noetic, and will be available
for ROS Melodic shortly. We can thus build the ROS binaries with HPP-FCL
support - provided that the BUILD_WITH_COLLISION_SUPPORT flag is toggled
to ON as a patch.

* package.xml: Remove unnecessary dependency on ament_cmake

* Ament index integration

* package.xml: Add clang dependency for buildfarm

Required by REP-136