New: Unmapped files view (#888)

* New: Unmapped files view

Displays all trackfiles that haven't been matched to a track.
Generalised the file details component and adds it to the album
details screen.

* Add sorting by quality

* New: MediaServiceTests & MediaRepoTests

frontend/src/TrackFile/ExpandingFileDetails.js

@@ -0,0 +1,83 @@
+import PropTypes from 'prop-types';
+import React, { Component } from 'react';
+import { icons } from 'Helpers/Props';
+import Icon from 'Components/Icon';
+import FileDetails from './FileDetails';
+import styles from './ExpandingFileDetails.css';
+
+class ExpandingFileDetails extends Component {
+
+  //
+  // Lifecycle
+
+  constructor(props, context) {
+    super(props, context);
+
+    this.state = {
+      isExpanded: props.isExpanded
+    };
+  }
+
+  //
+  // Listeners
+
+  onExpandPress = () => {
+    const {
+      isExpanded
+    } = this.state;
+    this.setState({ isExpanded: !isExpanded });
+  }
+
+  //
+  // Render
+
+  render() {
+    const {
+      filename,
+      audioTags,
+      rejections
+    } = this.props;
+
+    const {
+      isExpanded
+    } = this.state;
+
+    return (
+      <div
+        className={styles.fileDetails}
+      >
+        <div className={styles.header} onClick={this.onExpandPress}>
+          <div className={styles.filename}>
+            {filename}
+          </div>
+
+          <div className={styles.expandButton}>
+            <Icon
+              className={styles.expandButtonIcon}
+              name={isExpanded ? icons.COLLAPSE : icons.EXPAND}
+              title={isExpanded ? 'Hide file info' : 'Show file info'}
+              size={24}
+            />
+          </div>
+        </div>
+
+        {
+          isExpanded &&
+            <FileDetails
+              audioTags={audioTags}
+              rejections={rejections}
+            />
+        }
+      </div>
+    );
+  }
+}
+
+ExpandingFileDetails.propTypes = {
+  audioTags: PropTypes.object.isRequired,
+  filename: PropTypes.string.isRequired,
+  rejections: PropTypes.arrayOf(PropTypes.object),
+  isExpanded: PropTypes.bool
+};
+
+export default ExpandingFileDetails;