feat: Progressive Web App (PWA)

[Gautam-Hegde]

This PR introduces Progressive Web App (PWA) functionality to our CMS,

• users can install cms as a standalone app on their devices.(no more tab switches)
• w/ next-pwa package

Lighthouse report

Resolves #[Issue Number if there]

Checklist before requesting a review

• [x] I have performed a self-review of my code
• [x] I assure there is no similar/duplicate pull request regarding same issue