Add CloudEvents support to HTTP transport

[sdesaiLULA]

Provide the ability to send and receive wolverine envelope as cloud event for http transport. The earlier option was using binary serializer and not compatible with non dotnet systems. The cloud events structure gives readability and easy integration with other frameworks.

builder.Services.AddHttpClient(
    httpNamedClient,
    client =>
    {
        client.BaseAddress = new Uri("https://recepient");
        client.DefaultRequestHeaders.Add("Authorization", $"Bearer eyJ***");
    });

builder.UseWolverine(opts =>
{
    var transport = new HttpTransport();
    opts.Transports.Add(transport);
    // Publish all messages to the external http endpoint using the named http client
    // This will send a message in cloud event structure.
    opts.PublishAllMessages().ToHttpEndpoint(httpNamedClient, useCloudEvents: true, options: jsonOptions).SendInline();
    
    // If the httpendpoint supports native scheduled sends, use this, so Wolverine does't use in memory
    // opts.PublishAllMessages().ToHttpEndpoint(httpNamedClient, supportsNativeScheduledSend: true).SendInline();
});

// To handle single message over HTTP, send them to https://where-your-app-with-message-handlers/_wolverine/invoke
// with the content type `application/cloudevents+json`. The endpoint will convert cloud event to dotnet type and handle the message
// Register the WolverineHttpTransportClient for sending messages over HTTP
builder.Services.AddScoped<IWolverineHttpTransportClient, WolverineHttpTransportClientCloudEvents>();

[jeremydmiller]

@sdesaiLULA Might need you to be a little more careful with your changes. The HTTP transport pull requests broke every single HTTP test. Can you try to run tests locally before you push?