Enhancement: Allow direct video download instead of opening video in new tab first

### Impacted plugin

Jetpack, VideoPress

### Quick summary

When clicking the 'Download' button on a video, the video should be downloaded directly instead of first opening the video file in a new tab.

### Steps to reproduce

1. Add a video to a post using the VideoPress (or Video) block. Enable 'Allow download' in the block's privacy settings.
2. View the post and click the download button via the video's 'share' button (also see [related issue](https://github.com/Automattic/jetpack/issues/39115) about making this button more visible).

### A clear and concise description of what you expected to happen.

I would expect the download to begin when I click the button, opening the 'Save' dialog.

### What actually happened

Instead, the video file opens in a new tab. Users then have to relocate the 'Download' button via the video's menu:

### Impact

Some (< 50%)

### Available workarounds?

Yes, easy to implement

### If the above answer is "Yes...", outline the workaround.

Workaround is to open the video file in a new tab and click the download button again, but this is not a good UX as it requires multiple clicks, and the download button is in two different places.

### Platform (Simple and/or Atomic)

_No response_

### Logs or notes

Source: 8697774-zen

Start by locating the Jetpack VideoPress/Video block's share-menu Download button and reproduce the behavior with Allow download enabled. Trace how the button opens the video file, then verify that clicking it starts the browser's Save dialog directly rather than opening a new tab.

Written by the indexing model from the issue text.