func new installs older version of extensions

```bash
func init --worker-runtime node
func extensions install -p Microsoft.Azure.WebJobs.Extensions.DurableTask -v 2.0.0
func new -l JavaScript -t "Durable Functions orchestrator" -n foo
```

The last step changes the DurableTask extension to version 1.8.0. Expected it to stay at 2.0.0 because it's newer.

Start by reproducing the issue with the listed func init, extensions install, and func new commands, then trace the extension-version handling used by func new. Done means creating the Durable Functions orchestrator no longer downgrades Microsoft.Azure.WebJobs.Extensions.DurableTask from 2.0.0 to 1.8.0.

Written by the indexing model from the issue text.