feat: Add support for updatedTypes in metadata updates

[jeromelaban]

Related dotnet/aspnetcore#52937, corresponding PR in blazor: dotnet/aspnetcore#55347

This PR passes the updatedType parameter in order by the hot reload agent to properly invoke MetadatatUpdateHandler types.

[dotnet-policy-service]

Thanks for your PR, @jeromelaban.
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[jeromelaban]

Note, I'm not sure how to test this properly on the CI's side, considering it requires an integration from the Blazor as well. Thanks for the reviews!

[MackinnonBuck]

Thanks for the contribution, @jeromelaban!

We may also need to update this struct to have an UpdatedTypes property and update these tests to verify it.

[MackinnonBuck]

I've tested these changes locally; with a small fix, hot reload works and the updatedTypes argument gets correctly supplied to MetadataUpdateHandlers 🙂

I also verified that:

• Using the latest SDK with a project targeting an older TFM still works
  • This is because the extra arguments passed to the Blazor._internal.applyHotReload function are simply ignored in that case
• The changes in the aspnetcore PR work without the changes here
  • This is because I also made a small change over there allowing the updatedTypes argument to be null
  • This should allow us to merge both changes at the same time and not have to worry about dependency flow issues

[MackinnonBuck]

Thanks again for the contribution, @jeromelaban!

[MackinnonBuck]

(Just going to wait for the aspnetcore PR to pass all its checks to make extra sure that both ends are good-to-go before merging).