Make dashboard print a good error message when configuration is invalid

[JamesNK]

See #3119 (comment)

[leslierichardson95]

@JamesNK what configuration are you referring to here? Is it authentication related?

[JamesNK]

Configuration here: https://github.com/dotnet/aspire/tree/main/src/Aspire.Dashboard#net-aspire-dashboard

[KalleOlaviNiemitalo]

Startup error reporting has been problematic in my applications as well. I wonder if OptionsValidationException should be changed to override ToString() or Message to include OptionsType and OptionsName in addition to the failure messages; then those would be part of ILogger exception logging with no effort from applications. (If the options are bound to configuration, then it would be even better to include the configuration path in the log entry, but that looks much more difficult to implement.)