Log error when Bundles used with .NET Isolated

We've gotten some CRIs recently where customers have mistakenly configured bundles in host.json for .NET Isolated apps, and this causes the host to not load properly. Here's an example: https://portal.microsofticm.com/imp/v5/incidents/details/549026571. The fix for this issue is for the customer to remove the bundle spec, and the app then loads properly.

If this is not supported, the host should log an error (diagnostic) leading the customer to remove the config. We should also consider fixing the bug that we seem to have, and allow the host to start up by ignoring the config in .NET Isolated.

Use the host.json bundle configuration with a .NET Isolated app as the starting reproduction. Verify the host's current startup outcome, then define done as a diagnostic directing removal of the bundle configuration and/or successful startup when it is ignored, resolving which behavior is supported.

Written by the indexing model from the issue text.