rename all remaining packages to internal/ (#12418)

This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`

internal/event/target/testdata/contrib/nats_tls.conf

@@ -0,0 +1,7 @@
+port: 14225
+net: localhost
+
+tls {
+    cert_file:  "./testdata/contrib/certs/nats_server_cert.pem"
+    key_file:   "./testdata/contrib/certs/nats_server_key.pem"
+}