This commit fulfills a long-standing desire to get the extension using
the same network controller as mobile by removing NetworkController from
this repo and replacing it with NetworkController from the
`@metamask/network-controller` package.
The new version of NetworkController is different the old one in a few
ways:
- The new controller inherits from BaseControllerV2, so the `state`
property is used to access the state instead of `store.getState()`.
All references of the latter have been replaced with the former.
- As the new controller no longer has a `store` property, it cannot be
subscribed to; the controller takes a messenger which can be
subscribed to instead. There were various places within
MetamaskController where the old way of subscribing has been replaced
with the new way. In addition, DetectTokensController has been updated
to take a messenger object so that it can listen for NetworkController
state changes.
- The state of the new controller is not updatable from the outside.
This affected BackupController, which dumps state from
NetworkController (among other controllers), but also loads the same
state into NetworkController on import. A method `loadBackup` has been
added to NetworkController to facilitate this use case, and
BackupController is now using this method instead of attempting to
call `update` on NetworkController.
- The new controller does not have a `getCurrentChainId` method;
instead, the chain ID can be read from the provider config in state.
This affected MmiController. (MmiController was also updated to read
custom networks from the new network controller instead of the
preferences controller).
- The default network that the new controller is set to is always
Mainnet (previously it could be either localhost or Goerli in test
mode, depending on environment variables). This has been addressed
by feeding the NetworkController initial state using the old logic, so
this should not apply.
