chore: make authz recorder opt in (#20310)

The authz recorder is causing a lot of memory to be allocated, and is a
memory leak for websocket connections.

This change makes it opt-in on a per request basis (ontop of `isDev`).
To get the authz headers, use `Copy as cURL` on chrome and append the
header `x-authz-checks=true`.

coderd/apidoc/docs.go

@@ -13977,6 +13977,9 @@ const docTemplate = `{
                 "docs_url": {
                     "$ref": "#/definitions/serpent.URL"
                 },
+                "enable_authz_recording": {
+                    "type": "boolean"
+                },
                 "enable_terraform_debug_mode": {
                     "type": "boolean"
                 },