[Blazor] Support configuring hub options

[javiercn]

Fixes #49300

[DamianEdwards]

How exactly does this enable configuring the hub options? Are there existing extension methods on IServerSideBlazorBuilder that enable that so that now it's returned from AddServerComponents() they can be called?

[javiercn]

@DamianEdwards yes

[SteveSandersonMS]

How come this is being made public here and there's an explicit interface implementation below? Wouldn't just one of those be sufficient?

[SteveSandersonMS]

Perhaps this is to avoid a binary breaking change. I see the base interface has a default implementation of Services. AFAIK it would be source-compatible just to add the base interface and remove the property from IServerSideBlazorBuilder entirely, but perhaps that's binary-breaking.

Is that the reason or am I missing some point?

[javiercn]

This is an interface, it was already public.

I had to apply new because by making IServerSideBlazorBuilder extend IRazorComponentBuilder it was hiding the member. If I removed the ServiceCollection from here, it was a breaking change. We can take the breaking change if we want to, but that would impact any library that compiled against IBlazorServerBuilder so it just felt safer to do it this way.

[javiercn]

Is that the reason or am I missing some point?

We were both typing at the same time. Yes, its to avoid the binary breaking change.

[SteveSandersonMS]

While I've asked a question to clarify this, I think I have probably guessed the answer and in any case this looks uncontroversial (at least, not dangerous!) so seems very reasonable to just approve as-is.