* split the original meta-ros layer to
  meta-ros-common
  meta-ros-backports-warrior
  meta-ros1
  meta-ros1-melodic
  meta-ros2
  meta-ros2-crystal
  meta-ros2-dashing

* make various changes in the files for their new locations

* ros-generate-recipes.sh: update the generated/ros-distro.inc and
  rosdep-resolve.yaml files in the right directory

* don't move scripts/*
Signed-off-by: Martin Jansa <martin.jansa@lge.com>