BATS: `shfmt`

[gaelicWizard]

Description

shfmt -w test/*.bash test/*/*.bats

Motivation and Context

Chapter 4. Just cleaning up. This is built on top of #2033.

How Has This Been Tested?

shfmt -w and test/run

Types of changes

• [x] Enhancement (non-breaking change which improves something)

Checklist:

• [x] My code follows the code style of this project.
• [x] If my change requires a change to the documentation, I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [x] If I have added a new file, I also added it to clean_files.txt and formatted it using lint_clean_files.sh.
• [x] I have added tests to cover my changes, and all the new and existing tests pass.