PL:U Added BFTTF loading(Loading from System NAND dumps) (#1088)

* Added bfttf loading

We can now load system bfttf fonts from system archives AND shared memory dumps. This allows people who have installed their system nand dumps to yuzu to automatically get shared font support. We also now don't hard code the offsets or the sizes of the shared fonts and it's all calculated for us now.

* Addressed plu fixups

* Style changes for plu

* Fixed logic error for plu and added more error checks.