Explore Collections bootstrap upgrade

[megwalt]

Closes #3216

Changes

• Updates button text format on Explore tab buttons
• Adjusts triangle indicator so that it is visible on active tab
• Adds missing translation in 'My Collections' breadcrumb
• Adjusts responsive layout breakpoints
• Fixes masonry view item title text
• Adjusts pagination layout and colors

Issues

• Missing table view
• Missing view type buttons
• Masonry view icon not being set properly through config.view.masonry.icon_class
• Missing sort fields

These issues seem to be related to changes in setting config in app/controllers/oregon_digital/explore_collections_controller.rb. Once the issues have been resolved, I can go back in and update the bootstrap/CSS.

Screenshots