Added webpack.ProvidePlugin for most used imports

Removed imports of React, connect, PropTypes throughout
Removed the "React" in React.Component/PureComponent

app/javascript/gabsocial/features/ui/components/tabs_bar.js

@@ -1,9 +1,6 @@
-import React from 'react';
-import PropTypes from 'prop-types';
 import { NavLink, withRouter } from 'react-router-dom';
 import { FormattedMessage, injectIntl } from 'react-intl';
 import { debounce } from 'lodash';
-import { connect } from 'react-redux';
 import { isUserTouching } from '../../../utils/is_mobile';
 import { me } from '../../../initial_state';
 import { Link } from 'react-router-dom';