[19/n Dispatcher refactor] Remove findTouchStateWindowAndDisplay

In this we remove findTouchStateWindowAndDisplay method that allows
direct access to the TouchState and Introduce a new method
findTouchedWindowHandleAndDisplay which return only the windowHandle and
displayId.

Bug: 367661487
Bug: 245989146
Test: atest inputflinger_tests
Flag: EXEMPT refactor
Change-Id: I0d41ba7750ed8539ce07783b22c452f23d9d4cda