Blazor Linux hosting

[guardrex]

Fixes #24003

[guardrex]

@LeaFrock ... I'm still working on this, but you can probably comment on it at this point. I might spin up an Azure Linux VM (or two, Nginx configured and Apache configured) to test this guidance, but it's also possible that the product unit will review and sign-off on the PR next week without requiring me to run tests. If you get a chance to look this over, I thank you in advance for any feedback.

I'm especially concerned about the Apache part at this time. I'm going to research that Apache sub-app path configuration a bit further. I totally guessed 🙈 on how it might work. I'll get into Apache docs shortly for further updates.

I'm also concerned about the host ... we have 127.0.0.1 in https://docs.microsoft.com/aspnet/core/host-and-deploy/linux-nginx#configure-nginx ... but you provided 0.0.0.0 ... and the SignalR scale doc uses localhost. I'm going to go with localhost for consistency right now.

[LeaFrock]

I'm also concerned about the host... but you provided 0.0.0.0 ...

Never mind, it's a typo. If nginx is deployed on the same machine as blazor app, it should be localhost certainly. But in my production environment, nginx is deployed on another machine while the blazor app is hosted behind it in LAN. So it cannot use 127.0.0.1.

[guardrex]

Thanks @LeaFrock ... I'm still working on the PR, and I hope to perform some Apache testing for the Apache bits tomorrow (Monday). Let me know if you have any further feedback on the PR.

UPDATE (1/10): I'll need to check with management on the Apache config scenario. I see various config example for Apache (example 1, example 2) that are similar to what we show for Blazor Server-Linux (Apache) config that came over from the PU, but I can't say if it's worth the time (i.e., 💰) for me brush up on it relative to perhaps a PU member (e.g., Sourabh) advising on the guidance because the PU member might be able to just look and clarify the config instantly upon inspection.

[guardrex]

@LeaFrock ... I'm still working on this a little. Management didn't make a decision on Apache coverage yet, so I'm going to comment-out the Apache part for later. I'll work on this topic again for an upcoming overhaul on #19286. I'll work on the Apache piece later. For now, I might make a few more small changes, then I'll get this merged. Thanks again for your help and feedback on the PR.

[guardrex]

Ok ... I think we're good here for now. I'll be back to work on these a bit more on UE ("user experience") updates later, and we'll continue to receive feedback from the readers on them. Thanks again @LeaFrock! 🎸