feat(codegen): don't load contract state unless getter reads or writes it

[i582]

Closes #3363.

[Gusarich]

contract Test {
    get fun zero(): Int {      // does not read state
        return 0;
    }

    get fun bugTrigger() {
        self.zero();        // invokes zero() via the non-mutating wrapper
    }
}

->

FunC compilation error: /Users/daniil/Coding/tact/test.tact_Test.fc:63:28: error: cannot apply function $Test$_fun_zero : () -> ((), int) to arguments of type tuple: cannot unify type tuple with ()
      $self~$Test$_fun_zero();

[Gusarich]

This optimization can incorrectly skip generating contract_load() for getters that indirectly use initOf or codeOf via static functions. Currently, computeGettersEffects() only considers effects from the arguments of static_call and does not analyze the body of called static functions. As a result, it might misclassify getters as storage-independent when they're actually dependent on storage initialization.

Example that breaks with current implementation:

contract Child {
    fun justForCodesDict(): StateInit {
        return initOf Test();
    }
}

fun helper(): StateInit {
    // requires __tact_child_contract_codes initialized by $contract_load
    return initOf Child();
}

contract Test {
    x: Int = 0;

    receive() {
        self.x += 1;
    }

    get fun broken(): Cell {
        // computeGettersEffects sees no storage access here
        return helper().code;
    }
}

You should enhance the analysis to recursively examine the bodies of static functions invoked by getters, ensuring proper detection of storage dependencies and preventing runtime errors caused by omitted contract_load().