SWE-2 / SP-263: Better way to wait for grid refreshs, code cleanup at widget package

...nbis/uitest/infra/matcher/BrowserListsElementMatcher.java

.../systemsx/cisd/openbis/uitest/infra/webdriver/Action.java

...temsx/cisd/openbis/uitest/infra/webdriver/Refreshing.java

...cisd/openbis/uitest/infra/webdriver/WaitForRefreshOf.java

...isd/openbis/uitest/page/tab/AssignSamplePropertyType.java

...x/cisd/openbis/uitest/page/tab/ExperimentTypeBrowser.java

...systemsx/cisd/openbis/uitest/page/tab/ProjectBrowser.java

...penbis/uitest/page/tab/PropertyTypeAssignmentBrowser.java

...msx/cisd/openbis/uitest/page/tab/PropertyTypeBrowser.java

...systemsx/cisd/openbis/uitest/page/tab/RegisterSample.java

.../systemsx/cisd/openbis/uitest/page/tab/SampleBrowser.java

...temsx/cisd/openbis/uitest/page/tab/SampleTypeBrowser.java

...h/systemsx/cisd/openbis/uitest/page/tab/SpaceBrowser.java

...temsx/cisd/openbis/uitest/page/tab/VocabularyBrowser.java

...stemsx/cisd/openbis/uitest/type/PropertyTypeDataType.java

...a/ch/systemsx/cisd/openbis/uitest/type/Representable.java

.../systemsx/cisd/openbis/uitest/widget/AlertMessageBox.java

...e/java/ch/systemsx/cisd/openbis/uitest/widget/Button.java

...java/ch/systemsx/cisd/openbis/uitest/widget/Checkbox.java

...x/cisd/openbis/uitest/widget/DeletionConfirmationBox.java