[MARKENG-1317] [MARKENG-146] Maintenance: Update to Gatsby V4, cleared build warnings and decreased vulnerabilities

[brandonmcastillo]

• Updated npm scripts across Covid 19 APIs site.
• Node version is now v14.15.0
• Added an s to exclude key in gatsby-config sitemap due to new version reqs
• Added { } to import helmet due to React upgrade
• Updated components to fix linting build issues / components are now a function rather than const
• Decreased vulnerabilities to 19~ for security measures.
• GraphQL warnings are no longer present during npm run dev or build.
• Removed commented out CSS
• Moved linting packages to dev dependencies

2020 -> 2022