feat!: generate a self-signed certificate if no certificates are specified (#5973)

* feat: generate a self-signed certificate if no certificates are specified

Clouds like AWS automatically navigate to https://<ip-here>. This
allows us to bind to that immediately, serve a self-signed certificate,
then reroute to the access URL.

* Add new flag and deprecate old one

* Fix redirect if not using tunnel

* Add deprecation notice

* Fix TLS redirect

* Run `make gen`

* Fix bad test

* Fix gen

docs/api/general.md

@@ -780,6 +780,17 @@ curl -X GET http://coder-server:8080/api/v2/config/deployment \
       "value": true
     }
   },
+  "redirect_to_access_url": {
+    "default": true,
+    "enterprise": true,
+    "flag": "string",
+    "hidden": true,
+    "name": "string",
+    "secret": true,
+    "shorthand": "string",
+    "usage": "string",
+    "value": true
+  },
   "scim_api_key": {
     "default": "string",
     "enterprise": true,