Implemented PK3 deletion on incomplete processes; added error handling for sprites that go off bounds

Implemented PK3 deletion on incomplete processes; added error handling for sprites that go off bounds

• The program now deletes the generated PK3 file if it returns an error.
• Added error handler for sprites that go off bounds (usually if the image is smaller than the sprite dimensions as laid out by the properties file). Previously the program continued to run until it forced itself to close, resulting in a potentially corrupted PK3 file.
  • I would've made this its own MR but this portion of code would also need the change for PK3 deletion and I only wanted to have one MR out.