Cleanups (#3742)

* Remove unused file

* Combine tx checks into single file

* Move UI components into UI

* DRY links

* Unused rollup config

* Cleanup util paths

* Revert "Move UI components into UI"

This reverts commit 3379e61246cde635c296d31322b71e63395a5cd4.

* Re-apply ~/util/tx move

* Cleanup unused styles

js/src/ui/TxHash/txHash.js

@@ -20,7 +20,7 @@ import { connect } from 'react-redux';
 import { bindActionCreators } from 'redux';
 import { LinearProgress } from 'material-ui';
 
-import { txLink } from '../../3rdparty/etherscan/links';
+import { txLink } from '~/3rdparty/etherscan/links';
 import ShortenedHash from '../ShortenedHash';
 
 import styles from './txHash.css';