Fix deleting aggregate properties from within wxPG event handler.

Do not explicitly remove sub-properties of aggregate property because they will be removed automatically in their parent property dtor.

See #16459

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77485 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix deleting (from within wxPG event handler) properties not belonging to the current PG page.

Currently, it is not possible to remove properties from the page other then currently selected.
The scope of iterator used in wxPropertyGridPageState::DoClear() to enumerate properties must be limited to the required page and not always to the selected one.

Closes #16459

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77486 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775