[question] How to return 400 Bad Request status code or similar

For an Exposed Thing implementation, what are different errors we can return from an action invoke, property write etc. that is supported in node-wot?
At the moment, I have the following for an Action Handler:
```
(data) => {
return new Promise((resolve, reject) => {
if (!ajv.validate(this.thing.actions.myAction.input, data)) {
reject(new Error ("Invalid input")); // Need a better error message
} else {
resolve(this.move(speeds));
}
});
});
```
where ajv is a JSON Schema validator that validates the input payload to the input DataSchema. This code returns a 500 error in the case of HTTP Binding which means that there was something wrong in the HTTP Server internally.

I have looked at the Scripting API spec where the [setActionHandler method](https://w3c.github.io/wot-scripting-api/#the-setactionhandler-method) says that we should return [NotSupportedError](https://heycam.github.io/webidl/#notsupportederror) when we don't have a handle. This is not the case here, our case is more related to the ActionHandler itself. The spec says that this case should return an error but does not give details. A close inspection of [different error names in WebIDL](https://heycam.github.io/webidl/#idl-DOMException-error-names), it would be maybe suitable for this specific case to:
* Use [DataError](https://heycam.github.io/webidl/#dataerror). However, this means that the data is inadequate. The word inadequate however has a meaning like "not enough", "insufficient" (see [here](https://www.merriam-webster.com/dictionary/inadequate). This would be not 100% correct since maybe the data is simply wrong, like sending integer instead of string.
* Use [TypeError](https://heycam.github.io/webidl/#exceptiondef-typeerror). However, this would not be valid if the types match (sending an object when an object is asked) but the properties of this object is not correct, like sending `{"hey":"wot"}` whereas the server has a DataSchema like
```
{
"type":"object",
"properties":{
"key":{"type":"string"}
},
"required":["key"]
}
```

I am guessing that this is 80% scripting api issue but there has to be at least a way to return 4XX-like errors in node-wot.