fb4ff3e added a statistics option to show the internal resolution, but
it just showed the total size of the EFB (which is always 640x528) times
the IR scale, so it didn't convey any useful information.

This commit instead makes the option use the size of the last XFB copy
(not multiplied by the IR scale), which changes based on the game's
rendering resolution.

This makes the struct 8 bytes smaller.

Co-authored-by: Dentomologist <dentomologist@gmail.com>

Instead, we make the event take a reference to the system and then pass
it in when the event is triggered.

This does introduce two other accessors, but these are much easier to
refactor out over time, and without modification to the existing event
interface.

At the end of each frame automatically update the Current Value for
visible table rows in the selected and visible CheatSearchWidget (if
any). Also update all Current Values in all CheatSearchWidgets when the
State changes to Paused.

Only updating visible table rows serves to minimize the performance cost
of this feature. If the user scrolls to an un-updated cell it will
promptly be updated by either the next VIEndFieldEvent or the State
transitioning to Paused.