[chore] Replace chunks channel with ChunkReporter in git based sources (#2082)

ChunkReporter is more flexible and will allow code reuse for unit
chunking. ChanReporter was added as a way to maintain the original
channel functionality, so this PR should not alter existing behavior.

hack/snifftest/main.go

@@ -204,7 +204,7 @@ func main() {
 					})
 
 				logger.Info("scanning repo", "repo", r)
-				err = s.ScanRepo(ctx, repo, path, git.NewScanOptions(), chunksChan)
+				err = s.ScanRepo(ctx, repo, path, git.NewScanOptions(), sources.ChanReporter{Ch: chunksChan})
 				if err != nil {
 					logFatal(err, "error scanning repo")
 				}