[Feature Request]: Add open in Invidious instance to the Default Viewing Mode dropdown

### Guidelines

- [x] I have [searched the issue tracker for open and closed issues](https://github.com/FreeTubeApp/FreeTube/issues?q=is%3Aissue+sort%3Arelevance-desc) that are similar to the feature request I want to file, without success.
- [x] I have searched the [documentation](https://docs.freetubeapp.io/) for information that matches the description of the feature request I want to file, without success.
- [x] This issue contains only one feature request.
- [x] I have read and agree to follow the [rules](https://docs.freetubeapp.io/community/rules/).

### Problem Description

An user behind a VPN can't watch videos on Youtube. For a time, using the Invidious API instead worked fine to watch videos in Freetube, until LLM makers abused of them. Since them, to watch a video with no account (Youtube or Invidous) and behind a VPN, instead of a simple mouse click on the video, users have to click on the 3 dots and select "Open on Invidious". That makes a "huge" workflow (compared to watch videos on youtube), especially when the configured instance is down.

### Proposed Solution

Would it be possible to configure the default action when clicking on a video ? This way, the user could configure Freetube to open an invidious page in the user browser.
An additional nice "good to have" would be to be able to configure alternate actions while holding shift or alt. This would allow for example to open the video on the default invidious instance in the browser, or to do so on alternate instances with a click while holding shift or alt.
It would even be better if instead of a preset of actions it would be possible to execute a custom command.

### Alternatives Considered

Currently none, or maybe switching from Freetube to a given Invidious instance.

### Issue Labels

new feature

### FreeTube Version

v0.24.0 beta

### Operating System Version

Arch

### Installation Method

AUR (Unofficial)

### Upload screenshots or videos

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### Additional Information

_No response_