[BUG] - Cannot call a @method that returns a value directly from a transaction.

[MartinMinkov]

Description

If we define a method that returns a value (like in the composability example), we cannot call such method directly from a transaction() call.

This is currently happening on SnarkyJS 0.6.0

Reproduce

Given the following method:

@method callAddAndEmit(_x: Field, _y: Field): Field {
   ...
   return Field.one;
}

An error will occur when we attempt to directly call it in a transaction block

tx = await Mina.transaction(feePayer, () => {
  zkapp.callAddAndEmit(Field(5), Field(6));
});

The following stack trace is reported:

/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/_node_bindings/snarky_js_node.bc.cjs:7565
         throw err;
         ^

Error: Type "undefined" cannot be converted to a field element
    at raise_error (/home/martin/Code/o1/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/_node_bindings/snarky_js_node.bc.cjs:419334:44)
    at value$6 (/home/martin/Code/o1/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/_node_bindings/snarky_js_node.bc.cjs:419400:43)
    at caml_call_gen (/home/martin/Code/o1/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/_node_bindings/snarky_js_node.bc.cjs:2081:17)
    at /home/martin/Code/o1/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/_node_bindings/snarky_js_node.bc.cjs:3643:18
    at new eval (eval at caml_js_eval_string (/home/martin/Code/o1/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/_node_bindings/snarky_js_node.bc.cjs:3630:44), <anonymous>:4:26)
    at to_field_obj (/home/martin/Code/o1/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/_node_bindings/snarky_js_node.bc.cjs:419416:35)
    at /home/martin/Code/o1/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/_node_bindings/snarky_js_node.bc.cjs:419708:44
    at caml_call_gen (/home/martin/Code/o1/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/_node_bindings/snarky_js_node.bc.cjs:2081:17)
    at Function.<anonymous> (/home/martin/Code/o1/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/_node_bindings/snarky_js_node.bc.cjs:3643:18)
    at Function.Class.<computed> [as toFields] (file:///home/martin/Code/o1/mina/src/lib/snarky_js_bindings/snarkyjs/dist/node/snarky/proxy.js:21:62)