Editing Physics Core 2D settings in project settings window always requires finding and selecting the asset first

Steps to reproduce:

1. Create new project and create new PhysicsCore Settings 2D file in project window
2. In Project Settings, assign it to Physics Core Settings field under Physics Core 2D tab
3. Make sure Physics Core Settings is no longer selected in project window
4. In Project Settings, Click on Settings sub-menu under Physics Core 2D tab

Actual results: Message stating that Physics Core Settings 2D asset needs to be selected to edit the settings 

Expected results: Active Physics Core 2D settings should always be available for edit in Settings tab and/or it should be possible to make changes directly on the settings file without having to go to project settings afterwards

Reproducible with versions: 6000.6.0a2, 6000.5.0b2

Not reproducible with versions: 

Can’t test with versions: 

Tested on (OS): MacOS

Notes:

• If user wants to change project settings then a reasonable expectation would be that they could do that by opening project settings window, without needing to find a relevant file in Project window first. Current behaviour stands out from other settings that use similar project asset based workflow (like Input System, HDRP).