fix(b-table): set `aria-sort` when using `sortKey` and `no-local-sorting` (closes #6602)#6603

jacobmllr95 merged 2 commits intobootstrap-vue:devbootstrap-vue/bootstrap-vue:devfrom

Hiws:utilize-sortKey-if-providedHiws/bootstrap-vue:utilize-sortKey-if-providedCopy head branch name to clipboard