[iOS] Fix VoiceOver bugs for Parcel Tracking Magic Stack module

This CL:
* Adds the "see more" button in the package tracking module as an
  accessibility element to allow for VO traversal
* Prevents redundant VO traversal in the parcel tracking list
  half-sheet view
* Adds more context to the ellipsis button accessibility label

Low-Coverage-Reason: HARD_TO_TEST No integration test support yet
Fixed: 1504002, 1503996, 1503999
Change-Id: Ic66dfe23018ad0e0f5b3e3dfce8128f2699aeb38
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5049722
Commit-Queue: Hira Mahmood <hiramahmood@google.com>
Reviewed-by: Scott Yoder <scottyoder@google.com>
Cr-Commit-Position: refs/heads/main@{#1227554}