Functions that use RandomWalkTest() to have test.type options

Several functions use RandomWalkTest() to do the significance test. Some early functions were built when RandomWalkTest() had only one test type ("two.sided.approx") so they only have that option. Since RandomWalkTest() have more test type options now, all the functions should be able to use all the options.

The functions include: AbsBiasSS(), RPSS(), CRPSS(). RMSSS() and MSSS() have this functionality already (see !155 (comment 222090))