React: Create Divider component

[mimarz]

Its normal to use hr element for dividing content. We have quite a few instances where a divider should be used instead of top/bottom border.

Make a simple Divider component with color tokens and top/bottom margin.

color?: 'default' | 'subtle' | 'strong'

Use cases for a divider is for dividing content used in Card, DropdownMenu , Modal, Popover etc.

Use new divider color tokens: #1056

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Relevant: #1043

[mrosvik]

New divider color tokens was created in meeting 6.nov: #1056