Use Go 1.16 native embedding and remove go-bindata (#1151)

Co-authored-by: Sam Salisbury <samsalisbury@gmail.com>

internal/servers/controller/handler_ui.go

@@ -18,7 +18,7 @@ func handleUiWithAssets(c *Controller) http.Handler {
 	if c.conf.RawConfig.PassthroughDirectory != "" {
 		nextHandler = devPassthroughHandler(c.logger, c.conf.RawConfig.PassthroughDirectory)
 	} else {
-		nextHandler = http.FileServer(ui.AssetFile())
+		nextHandler = ui.Handler()
 	}
 
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {