[Draft][OpenMW-CS] Don't use custom QSortFilterProxyModel for Info tables

Addresses issue #4357 (closed)

This fix "falls back" to basic sorting methods used by base class IdTableProxyModel, and ditches InfoTableProxyModel. I'm not however sure if there's useful code in InfoTableProxyModel or if it should be removed completely. I don't see much use for it, especially if this will get merged: !512 (closed) .

Don't merge before properly reviewed!