text: Title: AIP-84 Custom list assets endpoint with latest event
  Body: ### Description
  
  Right now, the functionality of the Assets List in the UI is limited. We should create a custom GET `/ui/assets` endpoint to make it more useful.
  
  First, we should add `latest_asset_event` to the response object and allow the list of assets to be sorted by the latest asset event timestamp.
  
  ### Use case/motivation
  
  _No response_
  
  ### Related issues
  
  _No response_
  
  ### Are you willing to submit a PR?
  
  - [ ] Yes I am willing to submit a PR!
  
  ### Code of Conduct
  
  - [x] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
  