Avoid accessing destroyed `QTableWidgetItem` by retrieving the desired
path from the item before it's destroyed.
In `ResourcePackManager::Remove` pointers to the selected items in `m_table_widget`
were saved in the local variable `items` before calling `Uninstall`.
`Uninstall` called `RepopulateTable` which called
`m_table_widget->clear()`, destroying the table's descendants. Upon
returning to `Remove` `items` then pointed to some of those destroyed descendants, and
passing `items[0]` to `GetResourcePackIndex` resulted in a call to
`item->row()` which was a use-after-free.
Fixes https://bugs.dolphin-emu.org/issues/14095.
Dentomologist
37dd6c287e