Windows High Contrast mode styling issues

[adidahiya]

Follow-up issues from #5524

Environment

• Package version(s): @blueprintjs/core as of [core] feat: support windows high contrast mode #5524
• Operating System: Windows with High Contrast mode enabled
• Browser name and version: Edge

Styling issues

Listed below roughly in order of importance:

Active tab indicator is hard/impossible to see

Progress bar is invisible

Slider filled track is invisible

Non ideal state icon stroke has low contrast

we shouldn't apply the opacity adjustment in high contrast mode:

Skeleton styling has no effect

maybe we should make the text color transparent?

Tables

Not 100% sure what we should do here, but adding borders between all cells probably makes the most sense. Also a thicker border between row/col headers and the table body