Port mod validation, add build QOL features

[ShinyHobo]

https://www.nexusmods.com/baldursgate3/mods/1841/?tab=posts&jump_to_comment=127478319

Add attribute and node node checking.

• Each attribute node in an lsx file requires an id, type, and value field.
• Nodes require id.
• Display message for specific node path in file, with line number, with info on missing field
• Ignore .lsf file if matching .lsf.lsx file exists in same directory

Add basic xml error checking

• Add popup for displaying xml formatting errors
• Add lsx parsing
• Add loca.xml parsing
• Scan RootTemplate files for valid xml before merging

Port python script

• Mismatched UUIDs

Add QOL features

• Move "pak to Mods folder" toggle into main window
• Added textbox that displays last mod workspace selected
• Add Rebuild button
• Save rebuild location and reuse if the folder location still exists on program start up

[Syrchalis]

Would be nice if the "rebuild" button wouldn't disappear after closing and re-opening (e.g. updating) the program. Aka save the path to last rebuilt mod somewhere.