sidebar: Move the pulser into the sidebar directory

I'm soon going to put it into the same box as the Stack

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

ui/test_window.py

@@ -4,7 +4,7 @@ from lib import version
 from . import window
 from . import header
 from . import pane
-from . import pulser
+from sidebar import pulser
 from gi.repository import Gtk
 import sidebar
 import unittest

ui/window.py

@@ -7,7 +7,7 @@ gi.require_version("Gtk", "4.0")
 from gi.repository import Gtk
 from . import header
 from . import pane
-from . import pulser
+from sidebar import pulser
 
 Window = Gtk.ApplicationWindow()
 Grid = Gtk.Grid()