Wrap grid in viewport

The window is created from a resource file but is populated in code. We
want to move as much as possible into the resource file instead to
simplify maintenance.

Create a viewport in the window's resource file which we add the grid
to, then only the grid only has to be added to the viewport in code.

Signed-off-by: Marcus Karlsson <mk@acc.umu.se>
Move status bar to resource file

The status bar is added in code but can easily be moved to the window's
resource file. Move it to the resource file.

Signed-off-by: Marcus Karlsson <mk@acc.umu.se>