add check for supported firewall rule source and destination target types

[daniellemayne]

in StatefulFirewallTests the Before() method should check what source and destination target types are supported before trying to create firewall rules used for the revokeXXX tests.
This check is already present for the create rules tests and checks both source and destination (see source check below)

for( RuleTargetType t : support.listSupportedSourceTypes(vlanTest) ) {
if( t.equals(sourceEndpoint.getRuleTargetType()) ) {
supported = true;
break;
}
}
if( !supported ) {
tm.ok("Source type " + sourceEndpoint.getRuleTargetType() + " is not supported");
return;
}