This change updates the transport.Config .Dial and .TLS.GetCert fields
to use a struct wrapper. This indirection via a pointer allows the
functions to be compared and thus makes them valid to use as map keys.
This change is then leveraged by the existing global exec auth and TLS
config caches to return the same authenticator and TLS config even when
distinct but identical rest configs were used to create distinct
clientsets.
Signed-off-by: Monis Khan <mok@microsoft.com>
Kubernetes-commit: 01044903860c7e2463888c48db91270dc9c7281d
