Remove trailing spaces

I ran

find . -type f -name '*.yaml' -exec sed --in-place 's/[[:space:]]\+$//' {} \+

inside the repository (and did some other minor whitespace alignments in the batteries).

(Some of these files claim to be auto-generated, but after looking at the BGA generator script, the output no longer matches. I didn't touch other files because I'm not really sure which ones are obsolete and which ones aren't.)