Also wondering if UnnecessaryBlock should be ported from JS to Java

Originally posted by @zbynek in #6523 (comment)

Proposed Rule Name: UnnecessaryBlock

Proposed Category: Code Style.

Description: A block is unnecessary, if it is

a) not a class body/method body/body of a control statement/initializer block/... AND
b) not used to restrict the scope of a variable.

Code Sample:

public class Foo {
    public boolean bad(Object o) {
        {
            if(obj == null) return false;
        }
        return true;
    }

    public boolean good(Object o) {
        if(obj == null) return false;
        return true;
    }
}