Add systray option to "rescue" windows.

I realised that if the user directly applies a layout or a rule, there are no checks for if that rule is valid or not.
This means that you can accidentally send windows off-screen, making it really hard to get them back.

Previously, you could use `ALT+SPACE M` and use arrow keys to move it, create another rule to move the window back or
restore your current snapshot. Now, you can just open the systray menu, click "Rescue windows" and it will find any off-screen windows
and move them back to (0, 0) coords

Author: Crozzers

src/main.py

@@ -10,7 +10,7 @@
 from gui import TaskbarIcon, WxApp, about_dialog, radio_menu
 from gui.wx_app import spawn_gui
 from snapshot import SnapshotFile, SnapshotService
-from window import restore_snapshot
+from window import apply_positioning, from_hwnd, is_window_valid, restore_snapshot
 
 
 def update_systray_options():
@@ -41,7 +41,7 @@ def update_systray_options():
         if not snapshot.phony:
             continue
         layout_menu.append([snapshot.phony, lambda *_, s=snapshot: restore_snapshot([], s.rules)])
-    menu_options[6][1][1:] = layout_menu
+    menu_options[7][1][1:] = layout_menu
 
     rule_menu = []
     for header, ruleset in (
@@ -55,7 +55,7 @@ def update_systray_options():
         for rule in ruleset:
             rule_menu.append([rule.rule_name or 'Unnamed Rule',
                               lambda *_, r=rule: restore_snapshot([], [r])])
-    menu_options[7][1][:-2] = rule_menu
+    menu_options[8][1][:-2] = rule_menu
 
 
 def clear_restore_options():
@@ -69,6 +69,20 @@ def clear_restore_options():
         snap.clear_history()
 
 
+def rescue_windows(snap: SnapshotFile):
+    def callback(hwnd, _):
+        if not is_window_valid(hwnd):
+            return
+        window = from_hwnd(hwnd)
+        if not window.fits_display_config(displays):
+            rect = [0, 0, *window.size]
+            logging.info(f'rescue window {window.name!r} {window.rect} -> {rect}')
+            apply_positioning(hwnd, rect)
+
+    displays = snap.get_current_snapshot().displays
+    win32gui.EnumWindows(callback, None)
+
+
 if __name__ == '__main__':
     logging.basicConfig(filename=local_path('log.txt'),
                         filemode='w',
@@ -93,6 +107,7 @@ def clear_restore_options():
             TaskbarIcon.SEPARATOR,
             ['Most recent', lambda *_: snap.restore(-1)]
         ]],
+        ['Rescue windows', lambda *_: rescue_windows(snap)],
         TaskbarIcon.SEPARATOR,
         [
             'Snapshot frequency', radio_menu(