[SR][SR Tree] Add screen reader tree to interactive graph editor (#2062)

## Summary:
To make it easier for content authors (and us devs while we're still
working on the screen reader experience) to build the screen reader
experience for an interactive graph without constantly having to
turn on the screen reader, add a screen reader tree directly into
the editor.

To do this, I used `querySelectorAll()` to get the mafs container
and all its children, and read their `aria-label` and
`aria-describedby` attributes.

After building an object with the elements, roles, and attributes,
display a tree showing these in the editor.

![image](https://github.com/user-attachments/assets/4fe89f90-590c-4aeb-8847-1235a56ca31b)

Issue: https://khanacademy.atlassian.net/browse/LEMS-2714

## Test plan:
`yarn jest packages/perseus-editor/src/widgets/interactive-graph-editor/components/interactive-graph-sr-tree.test.tsx`

Storybook
- Go to http://localhost:6006/iframe.html?globals=&id=perseuseditor-widgets-interactive-graph--interactive-graph-circle&viewMode=story
- Update the whole graph aria label and description
- Update the correct graph
- Update the locked figures and their labels
- Confirm that the SR tree updates

Author: nishasy

Reviewers: benchristel, nishasy, catandthemachines, anakaren-rojas

Required Reviewers:

Approved By: benchristel

Checks: ✅ Cypress (ubuntu-latest, 20.x), ✅ Publish npm snapshot (ubuntu-latest, 20.x), ✅ Lint, Typecheck, Format, and Test (ubuntu-latest, 20.x), ✅ Check builds for changes in size (ubuntu-latest, 20.x), ✅ Publish Storybook to Chromatic (ubuntu-latest, 20.x), ✅ Check for .changeset entries for all changed files (ubuntu-latest, 20.x)

Pull Request URL: #2062

Author: nishasy

.changeset/four-avocados-raise.md

@@ -0,0 +1,6 @@
+---
+"@khanacademy/perseus": patch
+"@khanacademy/perseus-editor": patch
+---
+
+[SR][sr tree] Add screen reader tree to interactive graph editor

packages/perseus-editor/package.json

@@ -55,6 +55,7 @@
         "@khanacademy/wonder-blocks-form": "6.0.4",
         "@khanacademy/wonder-blocks-icon": "5.0.4",
         "@khanacademy/wonder-blocks-icon-button": "6.0.4",
+        "@khanacademy/wonder-blocks-pill": "3.0.4",
         "@khanacademy/wonder-blocks-switch": "3.0.2",
         "@khanacademy/wonder-blocks-timing": "6.0.1",
         "@khanacademy/wonder-blocks-tokens": "3.0.1",
@@ -82,6 +83,7 @@
         "@khanacademy/wonder-blocks-form": "6.0.4",
         "@khanacademy/wonder-blocks-icon": "5.0.4",
         "@khanacademy/wonder-blocks-icon-button": "6.0.4",
+        "@khanacademy/wonder-blocks-pill": "3.0.4",
         "@khanacademy/wonder-blocks-switch": "3.0.2",
         "@khanacademy/wonder-blocks-timing": "6.0.1",
         "@khanacademy/wonder-blocks-tokens": "3.0.1",