bug(AMF Decode): Buffer exhausted while reading 8 bits at offset 0 via just empty input or newline

To reproduce that extremly very simple, just drag AMF decode
then you will see an uncaught error

```js
AMF Decode - Error in https://gchq.github.io/CyberChef/modules/Encodings.js on line 2.

Message: Buffer exhausted while reading 8 bits at offset 0, context:
- [ye] Ue#marker
- [readField()] Ue#marker
- [read()] Ue
- [Ue.read()] Ue
```

Direct Test Link:
- https://gchq.github.io/CyberChef/#recipe=AMF_Decode('AMF3')&oenc=65001&oeol=VT
- https://gchq.github.io/CyberChef/#recipe=AMF_Decode('AMF3')&input=ChMBA2EFQAg&oenc=65001&oeol=VT
- https://gchq.github.io/CyberChef/#recipe=AMF_Decode('AMF3')&input=CRMBA2EFQAg&oenc=65001&oeol=VT

Start by running the linked AMF Decode recipes with empty input, a newline, and the provided sample data. Inspect the AMF Decode path associated with the error reported from Encodings.js. Done means these inputs no longer produce an uncaught buffer-exhaustion error and the existing sample cases still decode correctly.

Written by the indexing model from the issue text.