Ingest: Add metadata files structure

Add page to upload new metadata files from.
Add move from TS to current pipeline helper

Add helper function to move files from a transfer source location to a
path on the current pipeline. To enable this, add the location UUID to
the browse JS.
Ingest: Add metadata files javascript

Add endpoint to copy metadata files. Add JS and templates to display
the browser to select files.
Support metadata files added during Ingest

refs #6488

When writing the METS, check for a metadata.csv added to the SIP,
in addition to ones from the originating transfers.  Add conversion
of metadata.json to metadata.csv for files added during ingest.

Move metadata reminder to before processing metadata directory, so new
files are processed.
METS: Cleanup handling of parsed metadata from CSVs

Clean up data to be sane before passing to helper function. Adjust helper
function parameters and return value to work better with reingest.