chore(windows): remove wm_keymandebug messages and functions

Fixes #10050.

Removes the following unused identifiers:
* ::wm_kmdebug
* ::wm_keymandebug
* AppInt::DebugControlled()
* AITIP::WM_KEYMANDEBUG_CANDEBUG
* AITIP::WM_KEYMANDEBUG_GETUNICODESTATUS
* AITIP::WM_KEYMANDEBUG_GETCONTEXT
* AITIP::WM_KEYMANDEBUG_ACTION
* AITIP::WM_KEYMANDEBUG_RULEMATCH
* AITIP::DebugControlled()
* AITIP::IsDebugControlWindow()
* AITIP::GetDebugControlWindow()
* AITIP::Debug_FillContextBuffer()
* AIDEBUGINFO struct
* ::FillStoreOffsets()
* AIDEBUGKEYINFO struct

Removes overloads which are now no-ops:
* AITIP::HandleWindow()
* AITIP::IsWindowHandled()
* AITIP::QueueAction()