Add support for a custom URL Protocol to open and run a generation

[JustMaier]

As we try and make it easier for people to use and generate with models any where they do their generations, it starts to make sense to look at doing a custom url protocol.

Ideally the protocol would allow people to select their prefer generation provider/tool and would be able to take the following parameters:

• All general generation parameters (prompt, negative, seed, etc)
• Model/Model Hash
• Assets to grab (Models, TIs, Hypernetworks, VAEs, etc)

It might make sense for their to be a few different standard commands that run over the protocol:

• Generate an image
• Download an asset