Treat a single upper case letter as a type name in a dotted chain

[abashev]

Brings over google/google-java-format#731, a fix from google-java-format 1.14.

The bug

A dotted name is broken after its type-name prefix, and the prefix is found from the case of each segment: com.example.Foo.bar is a package, a class and a member. A single upper case letter such as Android's R counted as an all-caps constant, so a long resource reference found no prefix and broke at every dot:

    int resourceId = com.some
            .extremely
            .verbose
            .pkg
            .name
            .R
            .string
            .some_extremely_long_resource_identifier_that_exceeds_the_column_limit;

From upstream, with the author kept

• Treat single-character upper case identifiers as UpperCamelCase google/google-java-format#731 by Liam Miller-Cushon, commit authored by them: a single upper case letter is UpperCamelCase in TypeNameClassifier, so the chain keeps com.some.extremely.verbose.pkg.name.R.string together and breaks once, before the last segment. The upstream golden b26306390 and the two TypeNameClassifierTest assertions come with it, with the expected output in this project's style.

Checked

• The golden and the from("A") assertion fail on main and pass with the change.
• ./gradlew :open-java-format:test on JDK 21: 1501 tests, all green.
• The 15,747 files of the JDK 21 sources format exactly as before: no chain in the JDK turns on a single-letter class name.