Fix build

When doing a `python setup.py build` on my machine, I found that
`build/lib` would not end up with a compiled gresource file until the
second invocation of `python setup.py build`.

Before:

    $ python setup.py build
    running build
    running build_py
    creating build
    creating build/lib
    creating build/lib/mcg
    copying mcg/connectionpanel.py -> build/lib/mcg
    copying mcg/shortcutsdialog.py -> build/lib/mcg
    copying mcg/serverpanel.py -> build/lib/mcg
    copying mcg/application.py -> build/lib/mcg
    copying mcg/window.py -> build/lib/mcg
    copying mcg/playlistpanel.py -> build/lib/mcg
    copying mcg/utils.py -> build/lib/mcg
    copying mcg/coverpanel.py -> build/lib/mcg
    copying mcg/infodialog.py -> build/lib/mcg
    copying mcg/librarypanel.py -> build/lib/mcg
    copying mcg/client.py -> build/lib/mcg
    copying mcg/zeroconf.py -> build/lib/mcg
    copying mcg/mcg.py -> build/lib/mcg
    copying mcg/__init__.py -> build/lib/mcg
    copying mcg/albumheaderbar.py -> build/lib/mcg
    package init file 'data/__init__.py' not found (or not a regular file)
    compiling gresources
    compiling gschemas

    $ ls build/lib/mcg/data/
    ls: cannot access 'build/lib/mcg/data/': No such file or directory

Note how there is no data directory at all. Now check out what happens
on the second build:

    $ git status
    On branch main
    Your branch is up to date with 'origin/main'.

    Untracked files:
      (use "git add <file>..." to include in what will be committed)
            data/gschemas.compiled
            data/xyz.suruatoel.mcg.gresource

    nothing added to commit but untracked files present (use "git add" to track)

    $ python setup.py build
    running build
    running build_py
    package init file 'data/__init__.py' not found (or not a regular file)
    creating build/lib/mcg/data
    copying data/xyz.suruatoel.mcg.gresource -> build/lib/mcg/data
    compiling gresources
    compiling gschemas

    $ ls build/lib/mcg/data/
    xyz.suruatoel.mcg.gresource

That's because the first build generated the compiled schemas and
resources (you can see evidence of that in `git status`), and then the
second build was able to copy the gresource file over according to the
`package_data` rules. The fix I've introduced here is to just do the
compilations *before* we call `super(...).run(...)`. There might be
better ways of doing this, I'm not very familiar with packaging gtk
python applications.

Things were even worse for the gschemas.compiled file: in addition to
the ordering issue it's not even mentioned in `data_files`, so even if
it does exist, it doesn't have a chance to get copied over when
installed. So I've added it to the `data_files` section. I don't know if
that'll play nicely or not with the existing `--no-compile-schemas`
flag.

setup.py

@@ -29,17 +29,19 @@ class build_mcg(build_py):
 
 
     def run(self, *args, **kwargs):
-        super(self.__class__, self).run(*args, **kwargs)
         self._build_gresources()
         if not self.distribution.no_compile_schemas:
             self._build_gschemas()
 
+        # This will copy the package_data and data_files, so we need to do this
+        # *after* we've compiled resources and schemas.
+        super(self.__class__, self).run(*args, **kwargs)
+
 
     def _build_gresources(self):
         print("compiling gresources")
         subprocess.run(['glib-compile-resources', 'xyz.suruatoel.mcg.gresource.xml'], cwd='data')
 
-
     def _build_gschemas(self):
         print("compiling gschemas")
         subprocess.run(['glib-compile-schemas', 'data'])
@@ -92,7 +94,8 @@ setup(
             "data/icons/mcg.svg"
         ]),
         (os.path.join('share', 'glib-2.0', 'schemas'), [
-            "data/xyz.suruatoel.mcg.gschema.xml"
+            "data/xyz.suruatoel.mcg.gschema.xml",
+            "data/gschemas.compiled",
         ]),
         (os.path.join('share', 'locale', 'en', 'LC_MESSAGES'), [
             'locale/en/LC_MESSAGES/mcg.mo'