[core] fix(Tabs, Switch): improve high contrast mode support

[styu]

Partially addresses #5622

Changes proposed in this pull request:

Adds high contrast mode support for Blueprint tabs
I also ended up fixing the high contrast mode for switches in dark theme, since I noticed that as I was testing out the dark theme + high contrast combo for the tabs

Reviewers should focus on:

Do active/disabled/normal states look ok?

[blueprint-bot]

Add high contrast mode support for Blueprint tabs

Previews: documentation | landing | table | demo

[adidahiya]

Looks good in light theme.

Minor feedback: vertical tabs could probably use a highlighted background, but this is low priority since we don't see vertical tabs used often.

Dark theme indicators are still not getting the highlight color:

[styu]

The vertical tab background is kind of rough to deal with because we have !important here:

blueprint/packages/core/src/components/tabs/_tabs.scss

Lines 108 to 115 in 980c634

	.#{$ns}-tab-indicator-wrapper ~ & {
	// these properties are only for static markup, therefore
	// we never want them if there's a tab indicator
	/* stylelint-disable declaration-no-important */
	background-color: transparent !important;
	box-shadow: none !important;
	/* stylelint-enable declaration-no-important */
	}

[blueprint-bot]

fix switch outline, try and fix vertical/dark mode tabs

Previews: documentation | landing | table | demo

[blueprint-bot]

Fix more dark mode styles

Previews: documentation | landing | table | demo

[blueprint-bot]

disable

Previews: documentation | landing | table | demo