Collection level search - Add full text search in addition to metadata

[labradford]

Descriptive summary

In Hyku main, on a collection show page (both admin and public), you can perform a search to find works/collections within the collection. This search should function just as the main search bar for each tenant, searching the text of PDFs, and all metadata fields, but only within the collection.

Rationale

When a user does a search for items within a collection, it should return matches for the contents of the filesets as well as the work metadata

Expected behavior

Performing a search on a collection page should return matches to title, metadata and PDF contents

Actual behavior

When I search for a term inside a PDF attached to the work, there are no search result matches

Steps to reproduce the behavior

1. add a collection
2. add works to a collection
3. make sure at least one work has a pdf attachment
4. search for text within the pdf attachment on the collection show page (both admin and public)
5. make sure the correct work is returned in the search

Related work

This work is being contributed by the Palni/Palci project