Update collection landing page bootstrap to v4

[megwalt]

For #3218

Changes

• Header
  • Fix duplicated institution logo
  • Adjust responsive breakpoints
• Share link + Social links
  • Adjust border radius on text input so that it fits next to the ‘Copy’ button
  • Default to all elements of the section on one line except for small responsive breakpoint
• Advanced search
  • Align field label text to the left
  • Update responsive breakpoints to match production
  • Add the search icon to the ‘Search’ button
  • Adjust margin below the ‘Search’ button
  • Fix background of select elements when under ‘focus’ status
• Other
  • Hide divider at small responsive breakpoint
  • Adjust text wrap and button size to match production
  • Fix thumbnail sizes at different responsive breakpoints
  • Remove discontinued bootstrap classes
  • Adjust grids so that text remains on the screen at smaller breakpoints

Screenshots

Large screen

Medium screen

Small screen