Update information indexed for Transfers

refs #6131

All files in a Transfer will be indexed so that the metadata and logs will
be available to be viewed in the SIP Arrangement panel.  Indexing and
updating the index on a file do not verify that they are in the DB anymore.
The full file path is not indexed, but the relative path (including the
transfer folder) is.

Add a wrapper for search_raw that queries for MAX_QUERY_SIZE entries from
ElasticSearch.  The default number returned is 10, and there is no way to
request all entries that match a search.
Backlog search populates originals panel

refs #6131

Several updates to make the transfer backlog search populate the originals
panel in SIP Arrangement.

Backlog.js queries the dashboard, which queries ElasticSearch based on the
provided query parameters.  The resulting paths are rearranged into a format
that the Javascript file-explorer is expecting and returned.  Backlog.js
updates the originals panel and forces a re-render.

Cleanup of unneeded functions: originals content endpoint, create/delete JS
from backlog.js, backlog viewing template, remainder of originals pane
search code, misc other helper functions.