JsonEqual for DictionaryArray Only Compares Keys

[tustvold]

Describe the bug

impl<T: ArrowPrimitiveType> JsonEqual for DictionaryArray<T> {
    fn equals_json(&self, json: &[&Value]) -> bool {
        // todo: this is wrong: we must test the values also
        self.keys().equals_json(json)
    }
}

To Reproduce

Expected behavior

Additional context

[tustvold]

JsonEqual was removed in #2296