Rollup merge of #126105 - tmandry:fuchsia-scripts, r=lqd

Add debugging utils and comments to Fuchsia scripts

This should help when debugging a failure in the Fuchsia build in CI.

I plan to follow up with a PR to the testing section of the dev guide with more details, along with more improvements happening in the Fuchsia repo itself.

try-job: x86_64-gnu-integration

Author: fmease