Minor refactoring on ros2 humble Dockerfile

[pariaspe]

• Gather some apt install
• Review .env file and move some ENV rules to file
• Review the use of .deb files
• Sourcing to bashrc
• COPY instead of cloning RI repo and cp/mv files after
• check if colcon building is setting env vars
• colcon building
• Entrypoint or default cmd

[pawanw17]

• Gather some apt install (merged)
• Review .env file and move some ENV rules to file (no environment variables required to move) ([Humble].env updated to latest paths #290)
• Review the use of .deb files (it is faster to copy than downloading)
• Sourcing to bashrc (I think we can move the GAZEBO_MODEL_PATH to .env)

source /opt/ros/humble/setup.bash
export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH:/home/ws/install/custom_robots/share
source /usr/share/gazebo/setup.bash

• COPY instead of cloning RI repo and cp/mv files after (not required since Dockerfiles are now removed from RI)
• check if colcon building is setting env vars (It is)
• colcon building (Building fine)
• Entrypoint or default cmd (Entrypoint works fine in our scenario since most of the parameters are fixed and don't need to be overridden by the user.