CI: Only build new ADE image when ROS deps or contents of ade_image folder change.

Closes #630 (closed)

@sgermanserrano @left4taco or @jpsamper Can one of you look at these changes real quick? I'm not actually sure how the previous bash script was supposed to work but this new one gets the ROS dependencies from the generate_ros_deps job and moves them into tools/ade_image and then hashes all of the contents of the files in that directory. The job then tries to pull an image that contains that hash. If one exists, it pulls it and re-tags it with the file hash, the commit hash, and the branch name. If one doesn't exist, it builds a new one and tags it with those 3 as well. Subsequent jobs that need the container use the commit hash version.