Does not support keys with colon (:) characters

Given following JSON:
```json
{
"custom:groups": [
"foo",
"bar"
]
}
```

And the following JMESPath expression:
`contains(custom:groups[*], 'foo') && 'Admin' || 'Editor'`

Expected expression to evaluate to "Admin".

Also tried the following expressions without success:
`contains("custom:groups[*]", 'foo') && 'Admin' || 'Editor'`
`contains('"custom:groups[*]"', 'foo') && 'Admin' || 'Editor'`

Doesn't work at https://jmespath.org/ either, but maybe this use case is not supported?

Ref: https://github.com/grafana/grafana/issues/22986