feat(plugins-runtime): allow openPage() to toggle opening a new window

[mdbenito]

Summary

This PR adds the extension to the :openPage command in page-proxy and context with an additional parameter submitted here. The parameter allows toggling the current default behaviour of always opening new Pages in separate browser tabs/windows.

I believe this is necessary because it's AFAICT otherwise impossible for plugins to navigate to shapes outside the current page. As it is right now, the plugin is unloaded in the new browser tab, making any action subsequent to openPage impossible.

Open questions:

1. In order not to break expectations for API users, I've handled undefined in the second argument to have the previous behaviour. Maybe there's another preferred way of handling defaults.
2. I have also done this in the frontend's code, which is redundant, but I'm not sure what the release process is, and whether or not it is possible for someone to mix versions
3. I see that the page-proxy has an :openPage slot as well, but this is not exposed in the API. Should we add that? And if we do, wouldn't it make more sense to call it :open, since it's already inside Page?

[Alotor]

Thanks! Looks good to me. I'll wait to merge until MR in core is done.

[mdbenito]

Thanks! Looks good to me. I'll wait to merge until MR in core is done.

Regarding that PR, Andrey suggested that we use an options object, instead of positional parameters. This will require the introduction of a OpenPageOptions interface or some such. Does this sound good? Do you have any examples / pattern I should follow?

[niwinz]

penpot/penpot#7753 merged. I mention it here for reference of a discussion on that PR about how to extend it on future.