ENH: Add Configuration.evalModify() ... to perform evaluation of expressions that modify properties in place

[rbygrave]

  /**
   * Run eval of the given properties modifying the values if changed.
   */
  void evalModify(Properties properties);

Example use:

  @Test
  void evalModify() {
    final Properties properties = basicProperties();
    properties.setProperty("someA", "before-${foo.bar}-after");
    properties.setProperty("yeahNah", "before-${no-eval-for-this}-after");

    String beforeYeahNahValue = properties.getProperty("yeahNah");

    final CoreConfiguration config = new CoreConfiguration(new Properties());
    config.evalModify(properties);

    String someAValue = properties.getProperty("someA");
    assertThat(someAValue).isEqualTo("before-42-after");

    String afterYeahNahValue = properties.getProperty("yeahNah");
    assertThat(beforeYeahNahValue).isSameAs(afterYeahNahValue);
  }