Fix saving edited property value when wxPG property is in 'invalid value' state.

When wxPGProperty is loosing focus in 'invalid value' state its pending value should be stored before resetting property to 'normal' state  because this operation (wxPG::OnValidationFailureReset) also resets pending value.

Closes #16587


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77887 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
In wxPropertyGridPageState use Boolean member variables to store Boolean values.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77888 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775