[FEATURE] Pipedream REST API - List Workflows

**Describe the solution you'd like**
List Workflows for the current user or org

**Do you have a workaround?**
No

**Additional context**
https://pipedream-users.slack.com/archives/CPTJYRY5A/p1747732250225989

```
We're trying to achieve the following use-case
Our users can create their own workflows, or can use our pre-built workflows
We'll use these pre-built workflows as templates, duplicating them when one of our users selects one
We'll constantly create new workflows for them to choose from & select
Our users are not technical, and the pipedream frontend requires quite some technical expertise, so we want to build our own frontend
```