We want to convert NetworkController to TypeScript in order to be able
to compare differences in the controller between in this repo and the
core repo. To do this, however, we need to convert the dependencies of
the controller to TypeScript.
As a part of this effort, this commit converts
`shared/constants/metametrics` to TypeScript. Note that simple objects
have been largely replaced with enums. There are some cases where I even
split up some of these objects into multiple enums.
Co-authored-by: Mark Stacey <markjstacey@gmail.com>
Adds a property, `hookNames`, to each RPC method handler export in `app/scripts/lib/rpc-method-middleware` and a function, `selectHooks`, to select from them.
`createMethodMiddleware` receives a giant `opts` object that includes a bunch of different methods from `MetaMaskController` and its subcontrollers. Each method implementation only requires a subset of these methods to do its work. Because they need some kind of name, we call these methods "hooks". With this change, whenever an RPC method is called, `selectHooks` will be called to ensure that each method only receives the hooks that it needs in order to do its job.
This implementation is based on [work in `snaps-skunkworks`](https://github.com/MetaMask/snaps-skunkworks/blob/a3e1248/packages/rpc-methods/src/utils.ts#L17-L34) that will be merged in the near future.
