When getting the wrapper for the root node, we must give the container of the root node, not the endpoint, because they won't necessarily be the same for functions contained within functions.
For now don't allow the neighborhood to go all the way out to the outermostEnclosingFunction, because that causes bugs.
After this change, `enclosingFunctionBodyEndpointNeighborhood` doesn't match `enclosingFunctionBody` even when the function is small, which is undesired behavior. `enclosingFunctionBody` includes the arguments to the function whereas `enclosingFunctionBodyEndpointNeighborhood` does not. We should find a way to fix this.
This provides functionality for getting the token features associated with a
neighborhood around an AST node. It is strongly related to `FunctionBodies`.
Co-authored-by: Chris Smowton <smowton@github.com>
