scrollToLastItem(at:animated:) is not scrolling to bottom properly.

[hidayetozsoy]

The Bug
The scrollToLastItem(at:animated:) method is not scrolling to the bottom properly. It eliminates the gap between last cell and inputBarAccessoryView. This issue is visible in the video I recorded from the Example app of MessageKit. It seems the method only makes the last item completely visible without considering the bottom inset and eliminates the space between the inputBarAccessoryView and the message cell.

To Reproduce
Open Example MessageKit app, open Basic Example screen, wait for bots to send message, or you can send yourself, messagesCollectionView will scroll to bottom automatically. Then try to scroll manually, it will scroll a little bit more, which is expected when programatically scrolled.

Expected behavior
The gap between inputBarAccessoryView messagesCollectionView should be kept when programatically scrolled.

Screenshots

Environment

• What version of MessageKit are you using?
  4.2.0 (commit c7f278c)

• What version of iOS are you running on?
  IOS 17.0.1 on Simulator iPhone 15 Pro Max
  IOS 17.2.1 on Physical Device iPhone 13

• What version of Swift are you running on?
  Swift 5.9

• What device(s) are you testing on? Are these simulators?
  IOS 17.0.1 on Simulator iPhone 15 Pro Max
  IOS 17.2.1 on Physical Device iPhone 13

• Is the issue you're experiencing reproducible in the example app?
  Yes.

(I don't know why but GIF is not repeating, you can see it after refresh)

[hidoon]

I created a PR for this issue.
#1832

[luoshuaiqing]

Hi, I encountered a similar though different issue, as mentioned in the fix PR. Would really appreciate your help, thank you!