Show "Show Older" for transactions the user has not interacted with

Summary: Fixes T7454. We weren't triggering "Show Older" unless there were hidden events because of a previous interaction.

Test Plan:
  - Set page size to 3.
  - Viewed a task with ~10 transactions.
  - Before patch:
    - Only 3 most recent transactions visible, no way to see older ones.
    - Saw "show older" appear, paged backward through transaction histroy.
  - Also, interacted with task and then viewed it, made sure "show older" still works.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T7454

Differential Revision: https://secure.phabricator.com/D11963

src/view/control/AphrontCursorPagerView.php

@@ -79,6 +79,10 @@ final class AphrontCursorPagerView extends AphrontView {
     return $results;
   }
 
+  final public function getHasMoreResults() {
+    return $this->moreResults;
+  }
+
   public function willShowPagingControls() {
     return $this->prevPageID ||
            $this->nextPageID ||