Update to Blacklight 8.

[cbeer]

TODO:

• Update document configuration to use components not partials
• Look at funky edit button alignment on catalog#show?
  
• Pass the current block to the embed component. projectblacklight/spotlight#3244
• Fix facet text/chevron colors
• Fix add Page widget chevron color
• Fix results list view icon/title layout

• undefined local variable or method view_config for CustomViewerComponent when visiting show page for uploaded item

• alert modal close x icon missing
• Hide IIIF icon in gallery and masonry view
• move metadata even more the left with a smaller margin in the list results view
• adjust browse category lists view so there isn't so much margin
• in the masonry view the text displayed on hover looks bad

[taylor-steve]

Here are two things I noticed. Not sure if they are a part of this work or not.

1. /search?group=true&q=Senatorio&search_field=default&view=gallery with "Group by exhibit" selected.

• 'Group by exhibit' isn't visually selected
• Missing exhibit count?

prod:

stage:

2. Same /search?q=Senatorio&search_field=default search but with "All results" selected. Should the IIIF icon be down below to the right like the other search results?

Great work. Happy to approve if these issues aren't relevant.