Remove hardcoded qa selector in sidebar and make it dynamic

What does this MR do?

When we refactored the sidebar, we hardcoded several values like QA selectors and classes in the view.

Nevertheless, that data must be dynamic in order to reuse the code with other resources, like groups. This means that we need to reuse the same mechanism we're using for QA selectors in the other menu items.

Screenshots

In the following screenshots we can see that only the QA selectors' HTML has changed:

Before the MR	After the MR

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.