Decide flow between scan/eventuality/report

Scan now only handles External outputs, with an associated essay going over
why. Scan directly creates the InInstruction (prior planned to be done in
Report), and Eventuality is declared to end up yielding the outputs.

That will require making the Eventuality flow two-stage. One stage to evaluate
existing Eventualities and yield outputs, and one stage to incorporate new
Eventualities before advancing the scan window.

processor/scanner/src/report.rs

@@ -40,6 +40,20 @@ impl<D: Db, S: ScannerFeed> ContinuallyRan for ReportTask<D, S> {
 
     for b in next_to_potentially_report ..= highest_reportable {
       if ScannerDb::<S>::is_block_notable(&self.db, b) {
+        let outputs = todo!("TODO");
+        let in_instructions_to_report = vec![];
+        for output in outputs {
+          match output.kind() {
+            // These do get reported since the scanner eliminates any which shouldn't be reported
+            OutputType::External => todo!("TODO"),
+            // These do not get reported in Batches
+            OutputType::Branch | OutputType::Change => {}
+            // These now get reported if they're legitimately forwarded
+            OutputType::Forwarded => {
+              todo!("TODO")
+            }
+          }
+        }
         todo!("TODO: Make Batches, which requires handling Forwarded within this crate");
       }