Fixes some inconsistencies in ElementFindingTest.java

The convention is for almost all 87 methods in the ElementFinding-TestSuite as follows:

 - If a testMethodName endsWith: „shouldThrow“ the test expects a NoSuchElementException.class

6 methods do not follow this convention. This patch fixes it.

SideNote: This makes implementing WebDrivers easier, since one can implement one ValidationRule, which fulfills the convention mentioned above instead of sometimes throwing Exceptions and sometimes returning 0.