Implement label support for Jumps in cross-assembler

[Rian-Ismael]

The cross-assembler is fully functional, capable of generating machine code from zepa-assembly syntax. However, labels have not yet been integrated. The cross-assembler should be able to accept and process labeled jumps without requiring the direct memory address to be specified, thereby improving flexibility in the assembly code. Ensure that instructions like JUMP _label_name are properly translated into machine code with the correct address.