initial pass of .net bugfixes

[Dashron]

If you don’t provide a label or email in the grouping function the middleware dies silently.

E.g.

app.Use(async (context, next) =>
{
    context.Items["apiKey"] = context.Request.Headers["key"];
    await next(); //GETTING a null reference exception here
});

We would like…

1. A good way to get to that null reference exception. Our client knew how to get it, but I didn't! We should make any necessary changes and document how to see errors.
2. Only apiKey is required, so there shouldn’t be an error at all if we leave out the other fields.

Censored params are removed not censored

Other libs have [redacted-{character-count}], .net is just removing the value entirely

Support .net framework

.net framework is different than .net core. framework seems to be legacy from what I can tell