refactor(transport): implemented Bi stream based abstraction for actor communication with next loop override

app/.dart_tool/extension_discovery/README.md

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+Extension Discovery Cache
+=========================
+
+This folder is used by `package:extension_discovery` to cache lists of
+packages that contains extensions for other packages.
+
+DO NOT USE THIS FOLDER
+----------------------
+
+ * Do not read (or rely) the contents of this folder.
+ * Do write to this folder.
+
+If you're interested in the lists of extensions stored in this folder use the
+API offered by package `extension_discovery` to get this information.
+
+If this package doesn't work for your use-case, then don't try to read the
+contents of this folder. It may change, and will not remain stable.
+
+Use package `extension_discovery`
+---------------------------------
+
+If you want to access information from this folder.
+
+Feel free to delete this folder
+-------------------------------
+
+Files in this folder act as a cache, and the cache is discarded if the files
+are older than the modification time of `.dart_tool/package_config.json`.
+
+Hence, it should never be necessary to clear this cache manually, if you find a
+need to do please file a bug.