WIP - Send Postman Correct ID When Getting Collection

So this was a doozy (and I only found it by rampaging around renaming things into something
that seemed more consistent for me - see nearby commits).

Postman has two identifiers for most objects in most contexts:
 - `id`: This is a unique identifier for the object, and is (at least) shaped like a UUID
 - `uid`:  Same as ID, except that the creating users's ID is concatenated as a prefix.
       - IMPORTANT NOTE - This is NOT a UUID

Notably, the collections APIs all ask for the collection _id_ as the URL path parameter specifying
the collection you want to grab info for, _not_ the uid.  This could be an ambiguity in the API
docs (maybe it accepts both?  Maybe it _sometimes_ accepts both?), but it's not clear to me right now.

The naming of our variables here aren't very clear unless you're deep in the thick of it (and maybe
not even clear then).  What happened here (it looks like) is that someone mistook a `uid` for something
that made sense to stuff into a "UUID"-suffixed variable.

pkg/sources/postman/postman.go

@@ -303,7 +303,7 @@ func (s *Source) scanWorkspace(ctx context.Context, chunksChan chan *sources.Chu
 		if shouldSkip(collectionID.UUID, s.conn.IncludeCollections, s.conn.ExcludeCollections) {
 			continue
 		}
-		collection, err := s.client.GetCollection(ctx, collectionID.UUID)
+		collection, err := s.client.GetCollection(ctx, collectionID.ID)
 		if err != nil {
 			// Log and move on, because sometimes the Postman API seems to give us collection IDs
 			// that we don't have access to, so we don't want to kill the scan because of it.