passpoint: refactor PasspointEventHandler

Changes include:
- cleanup the callback interface
- remove dependency for ScanDetail
- remove unused code
- add unit tests

BUG: 31264540
TEST: build and run unit tests

Change-Id: Idab62a6e12bef7807e2ef8bc5aec4e46fbf965dc
6 files changed
tree: 7a4525d33ca42431303e60f55241a7bb60ae2bd9
  1. libwifi_hal/
  2. libwifi_system/
  3. service/
  4. tests/