Add new icons for Hosts page. Fix hosts list width on wide screens. (#128)

- Add new PNG files for the new icons in the left side navigation and the right side labels on the Hosts page.
- Rename the old `<Icon />` component to `<KolideIcon />` and create a new `<Icon />` component. The ultimate goal is to get rid of the `<KolideIcon />` and `<PlatformIcon />` components and use the encompassing `<Icon />` component for all icons. The full transition will be made when we have icon assets to replace all the kolide icons and platform icons. Currently, we don't.
- Rename the `icon_name_for_label.js` utility to `icon_name.js` because the utility now includes `iconNameForLabel()` and `iconNameForPlatform()` functions.
- Fixes issue #127.

frontend/components/forms/ConfigurePackQueryForm/ConfigurePackQueryForm.jsx

@@ -2,7 +2,7 @@ import React, { Component } from 'react';
 import PropTypes from 'prop-types';
 import { pull } from 'lodash';
 
-import Icon from 'components/icons/Icon';
+import KolideIcon from 'components/icons/KolideIcon';
 import Button from 'components/buttons/Button';
 import Dropdown from 'components/forms/fields/Dropdown';
 import Form from 'components/forms/Form';
@@ -142,7 +142,7 @@ export class ConfigurePackQueryForm extends Component {
             {...fields.version}
             options={minOsqueryVersionOptions}
             placeholder="- - -"
-            label={['minimum ', <Icon name="osquery" key="min-osquery-vers" />, ' version']}
+            label={['minimum ', <KolideIcon name="osquery" key="min-osquery-vers" />, ' version']}
             wrapperClassName={`${baseClass}__form-field ${baseClass}__form-field--osquer-vers`}
           />
           <Dropdown