Java text blocks aren't understood by clang-format

Since Java 15, the language has support for multi-line text blocks, e.g.:

```java
String myStr = """
hello
there
""";
```

These aren't understood by clang-format at all, e.g. it would format the snippet above as

```java
String myStr = "" "
    hello there "" ";
```

which is nonsense and doesn't even compile.

Tested on clang-format version 16.0.0.