Implement instruction: ADDA

[tjhancocks]

Feature Request
An implementation for the ADDA instruction needs to be added to the emulation layer. Below is a brief description of the ADDA instruction taken from the M68000 Programmers Reference Manual.

Adds the source operand to the destination address register and stores the result in the address register. The size of the operation may be specified as word or long. The entire destination address register is used regardless of the operation size.

Describe the solution you'd like
The solution should match the existing conventions and patterns used by other implemented instructions. At the time of reporting this only includes the ABCD instruction.

Describe alternatives you've considered
N/a

Additional context
N/a