Add instructions LAC, LAS, LAT

[Flu]

1. LAC – Load and Clear
2. LAS – Load and Set
3. LAT – Load and Toggle

To be clear, this requires implementing parser support for it as well as adding it to the emulator internal API.

Testing

Add files called test_files/test_lac.asm, test_files/test_las.asm and test_files/test_lat.asm in which you test each of these instructions and then make unit tests for them in tests/MainTests.hs.

More information

https://ww1.microchip.com/downloads/en/DeviceDoc/AVR-InstructionSet-Manual-DS40002198.pdf#page=85