[Box] Add `paddingBlock` and `paddingInline` support

[laurkim]

To reduce the need to explicitly write out:

  <Box paddingInlineStart="200" paddingInlineEnd="200" paddingBlockStart="400" paddingBlockEnd="400">
    // children
  </Box>

  <Box padding="200" paddingBlockStart="400" paddingBlockEnd="400">
    // children
  </Box>

and consolidate this to:

  <Box paddingInline="200" paddingBlock="400">
    // children
  </Box>

  <Box padding="200" paddingBlock="400">
    // children
  </Box>