Adds error message handling for SearchResults

Before, if your search query request had an error,
no error or messsage was displayed, making it seem
like it was still loading results.  This adds error
handling so that a message is displayed with a list
of errors that were returned from the server.  Also,
searching now properly works in IE.

fixes CNVS-16611

Test Plan:
* Enable "Better File Browsing" feature flag
* Go to any course's Files page
* Use the search box to search for something
  that's less than three characters long
* An error message should be displayed in the main file
  pane stating that 3+ characters are required for search

Change-Id: I2c341cfb326512fff1709722f1eb24b38e1ef847
Reviewed-on: https://gerrit.instructure.com/43758
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Clay Diffrient <cdiffrient@instructure.com>
Product-Review: Hilary Scharton <hilary@instructure.com>
QA-Review: Anna Koalenz <akoalenz@instructure.com>