ResourceManagerStringLocalizer should support throwing if name not found

[DamianEdwards]

Add the ability to configure the ResourceManagerStringLocalizer so that if a given resource name is not found it throws, rather than returning the key itself. This effectively makes it behave like the underlying ResourceManager API itself.

e.g.

public enum ResourceLookupBehavior
{
    UseNameIfNotFound,
    ThrowIfNotFound
}

public class ResourceManagerStringLocalizerFactory...
{
    ...
    public ResourceLookupBehavior ResourceLookupBehavior { get; set; } = ResourceLookupBehavior.UseNameIfNotFound;
    ...
}

[glen-84]

This could be used by other implementations of IStringLocalizer, so you might consider making it more generic (f.e. LookupBehavior / StringLookupBehavior / LocalizedStringLookupBehavior).

[Rick-Anderson]

If you could make it act like MVC does when it can't find a view - that is, MVC will list the folders searched, that would really help debug.

An unhandled exception occurred while processing the request. InvalidOperationException: The view 'About' was not found. The following locations were searched: /Views/Home/About.cshtml /Views/Shared/About.cshtml.

[Eilon]

Closing because there are no plans to implement this.