Add ability to import lua files from GResources

One of the nice features of gjs is that you can import modules from within a GResource. This leads to the common usage of applications shipping a single resource bundle or single executable and avoids doing extra blocking disk io.

Here is a basic implementation of this:

local lgi = require('lgi')
local Gio = lgi.require('Gio')

package.loaders[#package.loaders + 1] = function (str)
  if str:sub(1, 12) == 'resources://' then
    local data = Gio.resources_lookup_data(str:sub(13), Gio.ResourceLookupFlags.NONE)
    if not data then
      return ' - Failed to find data for that path!'
    end

    local str = data:get_data()
    if not str then
      return ' - Failed to get data for that path!'
    end

    local module = loadstring(str)
    if not module then
      return ' - Failed to load string for that path!'
    end
    
    return module
  end
end

local window = require('resources:///org/gnome/Foo/window.lua')

Now I am not overly familiar with the codebase or even Lua so I am unsure where this best belongs but any feedback on the idea would be appreciated.

No source file or test is named. Start by locating the package.loaders integration and the Gio.resources_lookup_data binding shown in the example, then determine how a resources:// module path should be handled. Done should include documented behavior for successful imports and the lookup, data, and loading failures described in the issue, with tests for those cases.