feat: Asset Browser and picker for XBlocks

[xitij2000]

Description

This creates a new "file_picker" page in the authoring MFE. This page can be used as an embedded file browser for XBlocks to use for selecting assets. When files are selected it posts a message back to the opener with the selected files so they can be used by the block.

Supporting information

This was discussed on the forums and on related issue.

Testing instructions

Currently testing this requires using an XBlock or other code running in the platform that supports this.

TBD

Other information

Some of the XBlocks here have been adapted to work with this.

Best Practices Checklist

We're trying to move away from some deprecated patterns in this codebase. Please
check if your PR meets these recommendations before asking for a review:

• Any new files are using TypeScript (.ts, .tsx).
• Avoid propTypes and defaultProps in any new or modified code.
• Tests should use the helpers in src/testUtils.tsx (specifically initializeMocks)
• Do not add new fields to the Redux state/store. Use React Context to share state among multiple components.
• Use React Query to load data from REST APIs. See any apiHooks.ts in this repo for examples.
• All new i18n messages in messages.ts files have a description for translators to use.
• Avoid using ../ in import paths. To import from parent folders, use @src, e.g. import { initializeMocks } from '@src/testUtils'; instead of from '../../../../testUtils'

[openedx-webhooks]

Thanks for the pull request, @xitij2000!

This repository is currently maintained by @bradenmacdonald.

Once you've gone through the following steps feel free to tag them in a comment and let them know that your changes are ready for engineering review.

🔘 Get product approval

If you haven't already, check this list to see if your contribution needs to go through the product review process.

• If it does, you'll need to submit a product proposal for your contribution, and have it reviewed by the Product Working Group.
  • This process (including the steps you'll need to take) is documented here.
• If it doesn't, simply proceed with the next step.

🔘 Provide context

To help your reviewers and other members of the community understand the purpose and larger context of your changes, feel free to add as much of the following information to the PR description as you can:

• Dependencies

  This PR must be merged before / after / at the same time as ...

• Blockers

  This PR is waiting for OEP-1234 to be accepted.

• Timeline information

  This PR must be merged by XX date because ...

• Partner information

  This is for a course on edx.org.

• Supporting documentation
• Relevant Open edX discussion forum threads

🔘 Get a green build

If one or more checks are failing, continue working on your changes until this is no longer the case and your build turns green.

🔘 Update the status of your PR

Your PR is currently marked as a draft. After completing the steps above, update its status by clicking "Ready for Review", or removing "WIP" from the title, as appropriate.

---

Where can I find more information?

If you'd like to get more details on all aspects of the review process for open source pull requests (OSPRs), check out the following resources:

• Overview of Review Process for Community Contributions
• Pull Request Status Guide
• Making changes to your pull request

When can I expect my changes to be merged?

Our goal is to get community contributions seen and reviewed as efficiently as possible.

However, the amount of time that it takes to review and merge a PR can vary significantly based on factors such as:

• The size and impact of the changes that it introduces
• The need for product review
• Maintenance status of the parent repository

💡 As a result it may take up to several weeks or months to complete a review and merge your PR.

[codecov]

Codecov Report

❌ Patch coverage is 54.54545% with 15 lines in your changes missing coverage. Please review.
✅ Project coverage is 95.43%. Comparing base (cc1af47) to head (308762c).

Files with missing lines	Patch %	Lines
src/files-and-videos/files-page/FilePickerPage.tsx	0.00%	9 Missing ⚠️
...d-videos/generic/table-components/TableActions.jsx	37.50%	5 Missing ⚠️
.../files-and-videos/files-page/FilesPageProvider.tsx	87.50%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3013      +/-   ##
==========================================
- Coverage   95.47%   95.43%   -0.04%     
==========================================
  Files        1383     1384       +1     
  Lines       32645    32688      +43     
  Branches     7481     7504      +23     
==========================================
+ Hits        31168    31196      +28     
- Misses       1421     1423       +2     
- Partials       56       69      +13     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.