Add PanelInteractor

Extracts behavior from QSTileHost into a separate object, but the
separate object is only available behind a flag.

Test: atest TileServicesTest ScreenRecordTileTest PanelInteractorTest
Fixes: 270388184
Flag: QS_PIPELINE_NEW_HOST
Change-Id: Ibc91ab97ecb9c52146f1107a96e7490535ad43c0