AppleHV enablement pass #2

* Use vfkit command line assembly
* Inject ignition file into guest using http over vsock
* Ready notification through use of vsock

[NO NEW TESTS NEEDED]

Signed-off-by: Brent Baude <bbaude@redhat.com>

vendor/github.com/gin-gonic/gin/render/yaml.go

@@ -0,0 +1,36 @@
+// Copyright 2014 Manu Martinez-Almeida. All rights reserved.
+// Use of this source code is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package render
+
+import (
+	"net/http"
+
+	"gopkg.in/yaml.v3"
+)
+
+// YAML contains the given interface object.
+type YAML struct {
+	Data any
+}
+
+var yamlContentType = []string{"application/x-yaml; charset=utf-8"}
+
+// Render (YAML) marshals the given interface object and writes data with custom ContentType.
+func (r YAML) Render(w http.ResponseWriter) error {
+	r.WriteContentType(w)
+
+	bytes, err := yaml.Marshal(r.Data)
+	if err != nil {
+		return err
+	}
+
+	_, err = w.Write(bytes)
+	return err
+}
+
+// WriteContentType (YAML) writes YAML ContentType for response.
+func (r YAML) WriteContentType(w http.ResponseWriter) {
+	writeContentType(w, yamlContentType)
+}