Export default namespace only in versionless-import

[vixalien]

When you try to do something like import Adw from 'gi://Adw' it fails, saying:

Module '"gi://Adw"' has no default export.ts(1192)

And this is because of this line in adw1.d.ts

declare module "gi://Adw" {
    export * from "gi://Adw?version=1";
}

which can be solved by rewriting it as following:

declare module "gi://Adw" {
// Notice `export { default }` instead of `export * `
    export { default } from "gi://Adw?version=1";
}

this PR combined with #2 closes #1