Some newer elements are missing the attribute data-testid

**Describe the bug**

This is a bug for writing automated tests against applications using clockface. There is a well established idiom of using the attribute `data-testid` to locate elements to be manipulated during automated testing. When looking to click through the new compressed navbar to open alerts-history, I discovered that the element ` ` has no `data-testid`. With the word 'trigger' in the class name this is an obvious candidate element for automated testing paths. Furthermore this button is covering the anchor element which does have a `data-testid` attribute, but which does not now trigger the sub menu animation.

**To Reproduce**
Steps to reproduce the behavior:
1. Open influxdata ui
2. Open developer tools console
3. Inspect the bell icon in the navbar
4. The button element contains no `data-testid` attribute

**Expected behavior**
When writing automated tests, I expect to find `data-testid` attributes, especially in elements that are targets for user activity. Data-testids, which should not be liable to change, make automated tests more stable.

**Currently rendered HTML**

```HTML

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Browser**
- OS: Ubuntu 20.04
- Browser Chrome
- Version 95

Start by locating the component that renders the cf-tree-nav--sub-menu-trigger button and inspect how its neighboring navigation elements receive data-testid attributes. Add a stable test identifier to the user-activated button, then verify that the rendered compressed navbar exposes it for automated tests.

Written by the indexing model from the issue text.