providing list structure as part of JWT attributes

### Proposal

I'd like to use the following template:
```
{{{jwt
        foo=["bar1", "bar2"]
}}}
```
that should result in the token having:
```
{
...
 "foo": ["bar1", "bar2"]
...
}
```
Or is there a way to achieve it with the current implementation?

### References

_No response_