refactor: get rid of `deduce()` methods to compute operands

[zmalatrax]

The current computeOperands() method is based on the production vm in Rust:

• Compute the operand address
• Read the value at the computed address
• If the read memory cell is empty, deduce the operand value from the other operands with deduce()

Burying this logic in multiple methods with their own switch-case flow is confusing. It can, and should be done in a simpler way, straightforwardly.