New: Manual import improvements (#683)

* New: Manual import improvements

 - Detect and merge import with files already in library.
 - Allow selection of album release from Manual Import modal.
 - Loading indicator while fetching updated decisions

* Disable release switching if user manually overrode release

frontend/src/InteractiveImport/Confirmation/ConfirmImportModal.js

@@ -0,0 +1,37 @@
+import PropTypes from 'prop-types';
+import React, { Component } from 'react';
+import Modal from 'Components/Modal/Modal';
+import ConfirmImportModalContentConnector from './ConfirmImportModalContentConnector';
+
+class ConfirmImportModal extends Component {
+
+  //
+  // Render
+
+  render() {
+    const {
+      isOpen,
+      onModalClose,
+      ...otherProps
+    } = this.props;
+
+    return (
+      <Modal
+        isOpen={isOpen}
+        onModalClose={onModalClose}
+      >
+        <ConfirmImportModalContentConnector
+          {...otherProps}
+          onModalClose={onModalClose}
+        />
+      </Modal>
+    );
+  }
+}
+
+ConfirmImportModal.propTypes = {
+  isOpen: PropTypes.bool.isRequired,
+  onModalClose: PropTypes.func.isRequired
+};
+
+export default ConfirmImportModal;