refactor: migrate apitool from netx to netxlite (#496)

I discovered which transport were used by apitool and made sure he gets the same transports now. While there, I discovered an issue with ooni/oohttp that has been fixed with cba9b1ce5e.

Part of https://github.com/ooni/probe/issues/1591

internal/netxlite/resolver_test.go

@@ -16,7 +16,7 @@ import (
 )
 
 func TestNewResolverSystem(t *testing.T) {
-	resolver := NewResolverSystem(log.Log)
+	resolver := NewResolverStdlib(log.Log)
 	idna := resolver.(*resolverIDNA)
 	logger := idna.Resolver.(*resolverLogger)
 	if logger.Logger != log.Log {