Clean up more Dockerfile templates and optimize removing/extracting multiple files

[lbussell]

Summary

• Decouple templates for extracting files cleaning up those files, so that we can have better control over how and when files are cleaned up
• Optimize removing multiple files by calling rm once instead of twice
• Combine extract-tarball and extract-zip files because they were similar
• Removed Dockerfile.linux.download-validate-file because it wasn't providing enough useful abstraction
• Fix extra whitespace in some Dockerfiles
• Minor fixes/tweaks to handling online shas which I'm working on separately

Related

• Refactor Linux Dockerfile templates to make changing shas easier #6500