See https://github.com/sharegate/craco/issues/61.
Updating to craco 3.3.1 resolves error when trying to install dependencies and build:
```
Error: Cannot find module '~/code/src/paritytech/fether/node_modules/react-scripts/config/webpack.config.dev'
```

See https://github.com/paritytech/js-libs/pull/90#discussion_r

- Add option to import a Parity Signer account. It is then stored in
local storage.

- Send transactions with Parity Signer accounts

- Refactor sendStore so that "token" (and chainId) is inside this.tx;
avoids having to pass `token` around every function, and it makes sense
to put it in the object since it is part of the tx info.

- Add account type (either node or signer) to accountsInfo

- Add account type to withAccount; output props are now `{account:
{address, type}}` instead of `{accountAddress}`

* Move toggle details buttons and associated methods and showDetails state into nav of TxForm component

* Pass showDetails down as props to TxDetails

* Remove previous attempt to display TxDetails like a popup above other fields
(i.e. remove form-details-wrapper and -details-value styles)