[roksanaz]

Motivation

Brings List.Item and List.Accordion in line with the latest MD3 list spec:

• Tokens, spacing and typography: padding, type and colour follow the spec instead of hardcoded sizes and the old expanded primary tint.
• Selected state: MD3 selected colors on List.Item and List.Accordion.
• Accordion motion: expand/collapse animation on the chevron and content.
• Typed slots: new leading and trailing props on List.Item. They take a node, so List.Item owns the layout instead of trusting the caller to apply the style and color passed to the left and right render props. They take precedence over left and right when both are passed.

This combines #5041, #5057 and #5042, which were stacked on each other.

Related issue

Related to #4976, #4930

Screenshots / Videos

Test plan

Open the List example and:

1. Compare one, two and three line rows against the spec.
2. Expand and collapse an accordion and check the chevron and content animate.
3. Check a selected row uses the primary container colors.
4. Check the leading and trailing slots render and pick up the item color, including in a selected row.

[github-actions]

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