Get all assertions working in JavascriptStatesTest::doMultipleSelectTriggerTests()

Problem/Motivation

Near the end of #1149078: States API doesn't work with multiple select fields, we tried to get JavascriptStatesTest::doMultipleSelectTriggerTests() to not just verify that changing the trigger gets the desired results, but also if you restore the trigger to the initial state, all the elements should go back to the initial state, too. Sadly, there seems to be some weirdness in the intersection between item FormAPI elements, isVisible(), chromedriver, and perhaps $trigger->setValue([]) which is causing some of the assertions to fail. However, manually inspecting the test HTML output, and manual testing, both indicate that the states code is really working. Since #1149078 is a 12 year old bug, it'd be sad to hold up committing the fix even longer while sorting out the "perfect" tests. Hence, this follow-up.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet