Bootstrap 5.2 compatibility

[cbeer]

• Use $border-color when we're outside of a table context #2780

• Update the search bar component to use bootstrap5-style input groups … #2782
  

• pagination should not have rounded corners (upstream bug: Erroneous border-radius inside Pagination twbs/bootstrap#36820)
  

• Re-do facets as bootstrap 5 accordions #2784
  

• show tools lost their button-y ness
  

• search history labels should be more centered
  

• advanced search fields lost their margin
  

• advanced search sort widget lost its interactive appearance:
  

• home page jumbotron button background disappeared (bootstrap 5 regression)
  

• modal styling is gone (bootstrap 5.1 didn't look so good either; is this a regression from Use the HTML dialog element to replace bootstrap modal behaviors #2671?)
  

• Create a seam for downstream applications to change the default search header #2831 facet link underlining is a bit much (bootstrap 5 regression)