Provide extensions for F#

Description

Here is how you would currently write a minimal API style bot in F#:

let builder = Host.CreateApplicationBuilder()

builder.Services
    .AddApplicationCommands()
    .AddDiscordGateway() |> ignore

let host = builder.Build()

host.AddSlashCommand("ping", "Ping!", Func<string>(fun() -> "Pong"))
    .UseGatewayEventHandlers() |> ignore

host.Run()

Currently, Func<string>(...) is needed for minimal API commands. To improve the experience, it would be needed to provide generic overloads with FSharpFunc<...>. This issue would also be resolved by https://github.com/fsharp/fslang-suggestions/issues/1131.

Of course extensions for services themselves would also be added.

I am also probably unaware of other places in which extensions for F# would be needed. Feel free to suggest them.

The package naming would be {PackageName}.FSharp, so for example it would be NetCord.Hosting.FSharp for NetCord.Hosting.

I think it would be better to write the extensions in F#, as only F# methods can be inlined and optimized by the compiler.

Start with the minimal API command example using AddSlashCommand and the service extension chain, then identify other service APIs that need FSharpFunc overloads. Review the proposed {PackageName}.FSharp naming, including NetCord.Hosting.FSharp, and determine the complete extension scope. Done means the F# extensions are defined and the minimal API experience no longer requires Func.