fix: RefFromWasmAbi should not drop JsType

[fhilgers]

Fixes #32

[siefkenj]

Thanks for this! Is there any way to get a test for this behavior?

[Pantamis]

Post Merge ACK

I ran the proposed test with and without the fix of this PR. With the fix the test pass, without the fix the test fail when it unwraps the result of validate_simple_data_ref with free of stack slot 127 suggesting that indeed, the JS value was freed during the two invocations of the validation closure in the ref case.

Big thank you for the fix and especially the explanation in the linked issue 🙏 I learnt so much from it !