go.mod: update to github.com/emicklei/go-restful/v3 v3.7.3

full diff: https://github.com/emicklei/go-restful/compare/v2.9.5...v3.7.3

- Switch to using go modules
- Add check for wildcard to fix CORS filter
- Add check on writer to prevent compression of response twice
- Add OPTIONS shortcut WebService receiver
- Add Route metadata to request attributes or allow adding attributes to routes
- Add wroteHeader set
- Enable content encoding on Handle and ServeHTTP
- Feat: support google custom verb
- Feature: override list of method allowed without content-type
- Fix Allow header not set on '405: Method Not Allowed' responses
- Fix Go 1.15: conversion from int to string yields a string of one rune
- Fix WriteError return value
- Fix: use request/response resulting from filter chain
- handle path params with prefixes and suffixes
- HTTP response body was broken, if struct to be converted to JSON has boolean value
- List available representations in 406 body
- Support describing response headers
- Unwrap function in filter chain + remove unused dispatchWithFilters

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/github.com/emicklei/go-restful/v3/web_service_container.go

@@ -0,0 +1,39 @@
+package restful
+
+// Copyright 2013 Ernest Micklei. All rights reserved.
+// Use of this source code is governed by a license
+// that can be found in the LICENSE file.
+
+import (
+	"net/http"
+)
+
+// DefaultContainer is a restful.Container that uses http.DefaultServeMux
+var DefaultContainer *Container
+
+func init() {
+	DefaultContainer = NewContainer()
+	DefaultContainer.ServeMux = http.DefaultServeMux
+}
+
+// If set the true then panics will not be caught to return HTTP 500.
+// In that case, Route functions are responsible for handling any error situation.
+// Default value is false = recover from panics. This has performance implications.
+// OBSOLETE ; use restful.DefaultContainer.DoNotRecover(true)
+var DoNotRecover = false
+
+// Add registers a new WebService add it to the DefaultContainer.
+func Add(service *WebService) {
+	DefaultContainer.Add(service)
+}
+
+// Filter appends a container FilterFunction from the DefaultContainer.
+// These are called before dispatching a http.Request to a WebService.
+func Filter(filter FilterFunction) {
+	DefaultContainer.Filter(filter)
+}
+
+// RegisteredWebServices returns the collections of WebServices from the DefaultContainer
+func RegisteredWebServices() []*WebService {
+	return DefaultContainer.RegisteredWebServices()
+}