Output Action Cable JS without transpiling and as ESM (rails#42856)

* Output Action Cable JS without transpiling and as ESM

* Retain umd version under the old name, generate ESM version + duplicate under new name

* Precompile JavaScripts for direct asset pipeline use

* We've dropped support for IE11

* Include deprecation notice for the old file reference

Thanks @rafaelfranca 👍

* Allow app to opt out of precompiling actioncable js assets

cc @rafaelfranca

* Add changelog entries

Author: David Heinemeier Hansson

actioncable/.eslintrc

@@ -3,7 +3,8 @@
   "rules": {
     "semi": ["error", "never"],
     "quotes": ["error", "double"],
-    "no-unused-vars": ["error", { "vars": "all", "args": "none" }]
+    "no-unused-vars": ["error", { "vars": "all", "args": "none" }],
+    "no-console": "off"
   },
   "plugins": [
     "import"

actioncable/CHANGELOG.md

@@ -1,3 +1,15 @@
+*   Compile ESM package that can be used directly in the browser as actioncable.esm.js.
+
+    *DHH*
+
+*   Move action_cable.js to actioncable.js to match naming convention used for other Rails frameworks, and use JS console to communicate the deprecation.
+
+    *DHH*
+
+*   Stop transpiling the UMD package generated as actioncable.js and drop the IE11 testing that relied on that.
+
+    *DHH*
+
 *   Truncate broadcast logging messages.
 
     *J Smith*