V2Application Compatability Changes

[WBHarry]

Heya! I haven't really used this module before, but a user of the module I'm currently making was interested in using it. So I noticed that the Popout module isn't handling foundry's V2 Applications.

I made some changes that allows my V2 application to render perfectly. And it doesn't seem to have any impact on V1 applications, since all I'm really doing is wrapping a JQuery context around some calls so that both the V1 and V2 apps can compute properly.

The only other thing I added was attaching a 'Popout' class to the main element. This is just something I think would be very usefull as it would allow modules to change their styling based on that class being present (something I needed).

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Could very well be some important stuff I'm not considering since I'm not deeply familiar with the code, but give it a think 😁

[Posnet]

Thanks for bringing ApplicationV2 support to my attention. However I'm unlikely to merge this request in the current state. I've read through the source for ApplicationV2, and since it is effectively a hard fork of the Application type, my preference is just to make corresponding popout2.js to handle the V2 apps independently. Though it is not actually quite that simple since they will need to share the window.ui proxy.

Separately, adding the popout class is not an option for the same reason I can't used the normal method for adding header buttons, there are event handlers that look for that class and take action that breaks popout out windows. Though this may have changed for ApplicationV2, and is another reason for having completely independent code paths for V1 and V2 applications.

[WBHarry]

Alrighty! Can close this PR then.
At the very least, the code as it stands is quite capable of handling v2 with some changes, that much I can attest 😁