Add new seo fields

[akuny]

Per GSA/site-scanning#730, add three new fields and update the logic for canonical URL scan.

[github-actions]

MegaLinter status: ✅ SUCCESS

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ CREDENTIALS	secretlint	yes		no	2.29s
✅ GIT	git_diff	yes		no	0.01s
✅ TYPESCRIPT	eslint	8	0	0	6.46s

See errors details in artifact MegaLinter reports on CI Job page
Set VALIDATE_ALL_CODEBASE: true in mega-linter.yml to validate all sources, not only the diff