redesign exhibition pages for navigation and sizing issues

[frabbott]

Example: https://dp.la/exhibitions/outsiders-president-elections/anti-outsider-platforms/know-nothing-party-1856

• fix problems created by "immersive" experience (x Close exhibition)
• navigation problems like Next/Previous, sidebar?
• Document/image viewer is too small
• Caption text is too small
• Some view item information link to Page Not Found, others are just missing

[mgiraldo]

from #513:

Survey feedback about current design:

• Exhibition navigation design - the next button is too far down on the page and can be missed. Should maybe be under the text.
• Also a number of positive comments about the exhibitions.
• Exhibitions should still have consistent navigation bar across the top.
• Exhibitions should have some search or filter capability to navigate to specific exhibitions.
• Not clear that there were multiple items on the exhibition pages. User thought those were the carousel images for the next pages rather than sub-items for that section of the exhibition.