Fix the handling of `# fmt: skip` when it's at a colon line (#3148)

When the Leaf node with `# fmt: skip` is a NEWLINE inside a `suite`
Node, the nodes to ignore should be from the siblings of the parent
`suite` Node.

There is a also a special case for the ASYNC token, where it expands
to the grandparent Node where the ASYNC token is.

This fixes GH-2646, GH-3126, GH-2680, GH-2421, GH-2339, and GH-2138.