Performance candidate: simplify complex selector chains in `table`

[mattnolting]

Complex chained selectors have a significant impact upon performance. When table was first implemented, th/tds didn't have an associated selector which resulted in targeting th/td instead of table__th/table__td. Now that we have selector access, targeting specific selectors, rather than elements, would provide significant performance benefits.

Visual regression testing should accompany this issue

[mcoker]

closing for now until this is planned

[mattnolting]

Update 7/30/24

We discussed w/design updating :first/:last-child specific padding to pf-m-inset which is not present by default. The addition would look something like:

@lboehling @andrew-ronaldson @kaylachumley can you advise which spacer sizes should be supported? Doesn't seem likely that xs, xl, 2xl would need support.

.pf-c-table .pf-m-inset-{size} {
  .#{$table}__td:first-child {
    padding-inline-start: var(--{size});
  }

  .#{$table}__td:first-child {
    padding-inline-end: var(--{size});
  }
}