Case-insensitive search with JMESPath

Simple question: How to do a case-insensitive searching with JMESPath?

Let's say to search for `foo` in this JSON:

```
[
"foo",
"foobar",
"barfoo",
"bar",
"baz",
"barbaz",
"FOO"
]
```

Here is the case-sensitive search query:

```
[?contains(@, 'foo')]
```

It will returns `["foo", "foobar", "barfoo"]` but it misses `"FOO"`.