ASP.NET Core OIDC/JWT Handlers should not have a direct dependency on the AAD JWT Library

### Is your feature request related to a problem? Please describe.
Right now, ASP.NET Core has a direct dependency on the AAD JWT library (token handler, token validation parameters etc). This library is primarily driven by its sponsor - the AAD team.

There are more JWT options in .NET - being able to plug in a different JWT implementation would be beneficial for the .NET ecosystem.

### Describe the solution you'd like
ASP.NET Core should own its main JWT validation abstractions and rather ship with an by-default integration with the preferred JWT library. If that is the "in-house" one - fine. But it should be possible to plug in different implementations - similar to the DI system.

### Additional context
https://github.com/AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet/pull/1687#issuecomment-912905994

https://github.com/AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet/issues/1574

https://github.com/AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet/issues/1516

https://twitter.com/ycrumeyrolle/status/1431544530357075968