[Task](ui): standardize user click event simulation method across our test suite

[franzheidl]

Task Description

In the tests for ui-components, we use a variety of methods to simulate user clicks. All of these are valid, but represent different approaches and at-the-time best practices:

Approach	Occurrences	Files
userEvent.click	124	19
Direct element.click()	50	15
fireEvent.click	22	6
userEvent.pointer	0	0

Most test suites are consitent internally, and some (Pagination, Tooltip) even mix approaches in a single file:

File	Current method(s)
SideNavigationItem/SideNavigationItem.test.tsx	fireEvent.click
SideNavigationGroup/SideNavigationGroup.test.tsx	fireEvent.click
SideNavigation/SideNavigation.test.tsx	fireEvent.click
Card/Card.test.tsx	fireEvent.click
StyleProvider/StyleProvider.test.tsx	fireEvent.click
Switch/Switch.test.tsx	element.click()
ModalFooter/ModalFooter.test.tsx	element.click()
Radio/Radio.test.tsx	element.click()
BreadcrumbItem/BreadcrumbItem.test.tsx	element.click()
Checkbox/Checkbox.test.tsx	element.click()
Pill/Pill.test.tsx	element.click()
NativeSelect/NativeSelect.test.tsx	element.click()
Icon/Icon.test.tsx	element.click()
TopNavigation/TopNavigation.test.tsx	element.click()
Button/Button.test.tsx	element.click()
TabNavigationItem/TabNavigationItem.test.tsx	element.click()
TextInput/TextInput.test.tsx	element.click()
Textarea/Textarea.test.tsx	element.click()
Pagination/Pagination.test.tsx	fireEvent.click + userEvent.click + element.click()
Tooltip/Tooltip.test.tsx	userEvent.click + element.click()

We should standardize here in favour of userEvent.click as it is the most modern, idiomatic and already most used approach.