Revamp the .NET core MVC quickstart

[kailash-b]

Description

Revamps the existing .NET MVC quickstart to match the latest quickstart standards.

Testing

• This change adds test coverage for new/changed/fixed functionality

Checklist

• I have added documentation for new/changed functionality in this PR or in auth0.com/docs
• All active GitHub checks for tests, formatting, and security are passing
• The correct base branch is being used, if not the default branch

[github-actions]

Summary

Status	Count
🔍 Total	51
✅ Successful	47
⏳ Timeouts	0
🔀 Redirected	3
👻 Excluded	1
❓ Unknown	0
🚫 Errors	0
⛔ Unsupported	0

Redirects per input

Redirects in main/docs/fr-ca/libraries.mdx

• [200] https://github.com/auth0-samples/auth0-maui-samples/tree/master/Sample | Redirect: Followed 1 redirect resolving to the final status of: OK. Redirects: https://github.com/auth0-samples/auth0-maui-samples/tree/master/Sample --> https://github.com/auth0-samples/auth0-maui-samples/tree/main/Sample
• [200] https://www.github.com/auth0/auth0-flutter/ | Redirect: Followed 1 redirect resolving to the final status of: OK. Redirects: https://www.github.com/auth0/auth0-flutter/ --> https://github.com/auth0/auth0-flutter/

Redirects in main/docs/quickstart/webapp/aspnet-core/index.mdx

• [200] https://dotnet.microsoft.com/download | Redirect: Followed 1 redirect resolving to the final status of: OK. Redirects: https://dotnet.microsoft.com/download --> https://dotnet.microsoft.com/en-us/download
  Full Github Actions output