Introduce cni-bridge-fp as CNI bridge plugin wrapper binary for CRI
testing.
With CNI `io.kubernetes.cri.pod-annotations` capability enabled, the user
can inject the failpoint setting by pod's annotation
`cniFailpointControlStateDir`, which stores each pod's failpoint setting
named by `${K8S_POD_NAMESPACE}-${K8S_POD_NAME}.json`.
When the plugin is invoked, the plugin will check the CNI_ARGS to get
the failpoint for the CNI_COMMAND from disk. For the testing, the user
can prepare setting before RunPodSandbox.
Signed-off-by: Wei Fu <fuweid89@gmail.com>