[Sb refactor] Add network scan results to wifi repo

Adds the `WifiManager.registerScanResultsCallback` information to
`WifiRepository`, and `areNetworksAvailable` to the `WifiInteractor`.
This allows us to fund the QS tile with information about any other
networks being available.

This logic should match exactly the information that comes from the old
data pipeline.

Test: tests in statusbar/pipeline
Bug: 291321279
Change-Id: Ic8a632ecb19b74d99896fd0aef038f3c147a0290