Remove Icons - ArcLight 1

Description: Remove all icons on display on the website. These include the following (see documentation below for images):

• repository icon is a building
• collection icon
• folder icon (this one is visible in Search Results, see filter by subseries results)
• the Online Access icon in green AND bookmark checkbox and icon
• file icon

For items with digital content, see issue #160 (closed) for more info about how to add a “View Online” button to search results, and issue #155 (closed) for items within the CONTENTS section on item pages.

See issue #15 (closed).

Documentation (More Info): https://docs.google.com/document/d/1mTd8jPfLCowoUrYaSf93eTpZQoIbCegwJptGgvjgwzQ/edit?usp=sharing