feature(tool/move): update files pointing to the moved document(s)

[OnkarRuikar]

• Fixes https://github.com/mdn/yari/issues/8292

• Changes are almost same as https://github.com/mdn/yari/issues/8372

The PR:

• updates move command to update referring documents.
• adds status(new) and l10n(translated content) frontmatter attributes to optionalFrontMatterKeys array. Without this change Document.saveFile() removes these from metadata.
• changed referringFiles type from array to set in delete command. When a dirctory is deleted multiple sub pages get deleted so the array was getting duplicate entries.

[teoli2003]

Can we have a review on this? @Claas or @LeoMcA ? #8372 proved valuable in keeping the number of flaws at bay.

A few refactoring (like CSS) are ahead of us (as part of Mozilla's initiative to improve discoverability and navigability) and this feature will be needed to lower significantly the amount of menial work needed.

[github-actions[bot]]

This pull request has merge conflicts that must be resolved before it can be merged.

[github-actions[bot]]

This pull request has merge conflicts that must be resolved before it can be merged.

[OnkarRuikar]

Closing because this has been implemented and thoroughly tested on content side.