Nested folders: Add folder actions to other tabs

[ashharrison90]

What is this feature?

• adds folder actions to the Alerting and Panels tabs
• creates new page components for these tabs. this is for a couple of reasons:
  • so they can use the rtk query method to get the folder information (same as Dashboards tab)
  • so they can build the navModel in a programmatic way (same as Dashboards tab)
• implements move/delete in the folder actions

Why do we need this feature?

• better UX

Who is this feature for?

• anyone using nested folders!

Which issue(s) does this PR fix?:

Fixes #

Special notes for your reviewer:

Please check that:

• It works as expected from a user's perspective.
• If this is a pre-GA feature, it is behind a feature toggle.
• The docs are updated, and if this is a notable improvement, it's added to our What's New doc.

[joshhunt]

Good with code, and gave it a spin and works well with nested folders enabled. I want to test as well when disabling the feature flag before giving it my ✔️

[joshhunt]

Can I be a pain and ask if we can write tests for this?

Something like

describe("BrowseFolderAlertingPage", () => {
    it("renders correct breadcrumbs"); 
    it("renders folder name");
    it("renders alerts for folder");
    it("shows the alerting tab as selected")
});

Likewise for the other one? 🥺

[joshhunt]

I would like to discuss this with the wider frontend group - is there a better home where these fixtures can live? Maybe we could put a TODO on this to find a better home for it?

Personally, I would like to extend this fixtures pattern we/I started in browse-dashboards to the rest of the codebase...

[ashharrison90]

have moved these into separate fixtures files, still in the browse-dashboards folder for now. should make it very easy to move them later (e.g. if we want to move the libraryElements fixtures to the libraryPanels folder)