Apire Entity Framework integrations: Provide corresponding 'Add<Database>DbContextFactory' method

[mip1983]

At the moment with an EF database aspire integration you can use a method like 'builder.AddCosmosDbContext' (link) to register the dbContext for DI. It would be nice if there was a similar 'AddCosmosDbContextFactory' method.

It's often handy to have a factory in situations where you want to control the lifetime a bit more tightly to a method rather than at the service level (like where that service is consumed by something long running like a signalR connection, perhaps Blazor server).

As an aside, if you register the cosomos dbContext without the aspire extension method (and use 'enrich' after), what do you provide for the 'TokenCrediential' argument in the context of an Aspire app (assuming it's not using the key like it did previously)?