## Description
Adds a func in graphConnector that reduces
siteIDs and webURLs into a set of siteIDs. This
will be used by callers such as the CLI to
generate id-based selectors for sites even if
they handle webURLs as an alternative id.
## Type of change
- [x] 🌻 Feature
## Issue(s)
* #1616
## Test Plan
- [x] ⚡ Unit test