* add function to check if url is localhost
* allow localhost rpcUrls in `wallet_addEthereumChain`
* allow localhost blockExplorerUrls
* wrap new URL in try/catch
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.
Micaiah Reid
Niranjana Binoy
Ariella Vu
Erik Marks
Brad Decker