App builder extension method to register extension options

[liliankasem]

Issue describing the changes in this PR

Related issue: #1826

Pull request checklist

• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• My changes should not be added to the release notes for the next release
  • Otherwise: I've added my notes to release_notes.md
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• I have added all required tests (Unit tests, E2E tests)

[liliankasem]

@mattchenderson we will need to update the docs to make sure folks are aware that if they use Cosmos, Tables or Blob extensions, they will need to register via the ext method:

module Program

open Microsoft.Extensions.Hosting
open Microsoft.Azure.Functions.Worker

module Program =
    [<EntryPoint>]
    let main _ =
        let hostBuilder = new HostBuilder()

        // FSharp applications need to configure the Cosmos, Blob and/or Table extensions manually.
        hostBuilder.ConfigureFunctionsWorkerDefaults(fun (context: HostBuilderContext) (appBuilder: IFunctionsWorkerApplicationBuilder) ->
            appBuilder.ConfigureCosmosDB() |> ignore
            appBuilder.ConfigureBlobStorage() |> ignore
            appBuilder.ConfigureTables() |> ignore
        ) |> ignore

        let host = hostBuilder.Build()
        host.Run()

        0

Probably calls for a templates update as well