Fix URI format for res scheme

[jwortmann]

With a recent Pyright version, some features don't work (i.e. error in console or error dialog) for package ressource files (View Package File from the command palette).

This is because we use Packages as the authority name in res: URIs, and the authority is converted to lowercase by vscode-uri library in the server responses. Instead, we should move Packages to be part of the path component of the URI and leave authority empty.

See: microsoft/pyright#7495

---

The only case where I can find res:// being used in the Sublime Text API is in minihtml for the <img> element, see https://www.sublimetext.com/docs/minihtml.html#tags:

<img> — supports PNG, JPG and GIF images from file://, res:// and data: URLs.

For example with Terminus installed (as .sublime-package from Package Control), try in the console:

• works:

  view.show_popup('<img src="res://Packages/Terminus/images/link.png"/>')

• doesn't work:

  view.show_popup('<img src="res:/Packages/Terminus/images/link.png"/>')

But I consider this a bug or bad design in ST, they also should better support/use a single slash in res URIs.

Edit: The builtin run_macro_file command also supports res:// URIs for its command argument.