Implement the download_file widget action

[weeman1337]

Implements usage of the download_file action of the Widget API.
See MSC4039 .

Also moves the UploadImagePage page to ImagePage since it now demos up- and download of content.

Needs matrix-org/matrix-react-sdk#12931

✔️ Checklist

• A changeset describing the change and affected packages (more info).
• Added or updated documentation.
• Tests for new functionality and regression tests for bug fixes.
• Screenshots or videos attached (for UI changes).
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[changeset-bot]

🦋 Changeset detected

Latest commit: a1e0dea

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@matrix-widget-toolkit/api	Minor

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[HarHarLinks]

something is wrong, the upload happens 3 times every time i try it:

[HarHarLinks]

test setup: matrix-org/matrix-widget-api#99 (comment)

[HarHarLinks]

matrix-widget-api was merged and released as 0.9.0, matrix-react-sdk was merged and is slated for the next element-web release cycle (RC on 2024-09-03 and release on 2024-09-10).

[HarHarLinks]

one missing part appears

diff --git a/example-widget-mui/src/ImagePage/ImagePage.test.tsx b/example-widget-mui/src/ImagePage/ImagePage.test.tsx
index 69233d9..9842b7a 100644
--- a/example-widget-mui/src/ImagePage/ImagePage.test.tsx
+++ b/example-widget-mui/src/ImagePage/ImagePage.test.tsx
@@ -95,6 +95,7 @@ describe('<ImagePage>', () => {
         ROOM_EVENT_UPLOADED_IMAGE,
       ),
       WidgetApiFromWidgetAction.MSC4039UploadFileAction,
+      WidgetApiFromWidgetAction.MSC4039DownloadFileAction,
       WidgetApiFromWidgetAction.MSC4039GetMediaConfigAction,
     ]);

[mgcm]

🚀