+BLOCKED, +UNBLOCKED, and +BLOCKING tags

These are somewhat expensive tags, as they require reference to values
outside of the task itself.

To accomplish this, the replica supplies a pre-computed DependencyMap
that is only calculated once per replica, and only from the working set.

cli/src/invocation/report.rs

@@ -406,9 +406,12 @@ mod test {
         let task = replica.get_task(uuids[0]).unwrap().unwrap();
         assert_eq!(
             task_column(&task, &column, &working_set),
-            s!("+PENDING +bar +foo")
+            s!("+PENDING +UNBLOCKED +bar +foo")
         );
         let task = replica.get_task(uuids[2]).unwrap().unwrap();
-        assert_eq!(task_column(&task, &column, &working_set), s!("+PENDING"));
+        assert_eq!(
+            task_column(&task, &column, &working_set),
+            s!("+PENDING +UNBLOCKED")
+        );
     }
 }

cli/src/macros.rs

@@ -15,12 +15,13 @@ macro_rules! argv {
 // NOTE: in Rust 1.56.0, this can be changed to HashSet::from([..])
 #[cfg(test)]
 macro_rules! set(
-    { $($key:expr),+ } => {
+    { $($key:expr),* $(,)? } => {
         {
+            #[allow(unused_mut)]
             let mut s = ::std::collections::HashSet::new();
             $(
                 s.insert($key);
-            )+
+            )*
             s
         }
      };