Move private registry sources out of util package

Author: mbg

go/extractor/registries/BUILD.bazel

@@ -1,4 +1,4 @@
-package util
+package registries
 
 import (
 	"encoding/json"

go/extractor/util/registryproxy.go go/extractor/registries/registryproxy.gogo/extractor/util/registryproxy.go renamed to go/extractor/registries/registryproxy.go

@@ -1,4 +1,4 @@
-package util
+package registries
 
 import (
 	"testing"

go/extractor/util/registryproxy_test.go …tractor/registries/registryproxy_test.gogo/extractor/util/registryproxy_test.go renamed to go/extractor/registries/registryproxy_test.go go/extractor/util/registryproxy_test.go renamed to go/extractor/registries/registryproxy_test.go

@@ -10,6 +10,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/github/codeql-go/extractor/registries"
 	"github.com/github/codeql-go/extractor/util"
 )
 
@@ -140,7 +141,7 @@ func SupportsWorkspaces() bool {
 // Constructs a `*exec.Cmd` for `go` with the specified arguments.
 func GoCommand(arg ...string) *exec.Cmd {
 	cmd := exec.Command("go", arg...)
-	util.ApplyProxyEnvVars(cmd)
+	registries.ApplyProxyEnvVars(cmd)
 	return cmd
 }