Very final release

Changelogs:

• Change the favicon, and some web icons. 45b7e52
• Upgrade some dependencies (17+ dependencies)
• Added support for Android 11 (bump targetSdkversion to 30)
• Added link to Google Play Store if user open from the web
• Introducing copy feature for web users.
• Fix snackbar scaffold deprecated issue.

Get the app on Google Play Store: https://play.google.com/store/apps/details?id=live.iqfareez.bmicalculator
or run on / download from the web: https://bmi-flutter-2e776.web.app/