This plumbs a packet filter for jailed nodes through to the
tstun.Wrapper; the filter for a jailed node is equivalent to a "shields
up" filter. Currently a no-op as there is no way for control to
tell the client whether a peer is jailed.
Updates tailscale/corp#19623
Co-authored-by: Andrew Dunham <andrew@du.nham.ca>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Change-Id: I5ccc5f00e197fde15dd567485b2a99d8254391ad