Refactor common and fancyzones/utils (#6073)

* Move module-specific functions to module

* Refactor FZ utils

* Remove 'zonable' from FancyZonesWindowInfo

* Address PR comments

* Address PR comments

* Fix stuff after rebasing

src/common/common.h

@@ -13,24 +13,8 @@ std::optional<RECT> get_button_pos(HWND hwnd);
 std::optional<RECT> get_window_pos(HWND hwnd);
 // Gets mouse position.
 std::optional<POINT> get_mouse_pos();
-
-// Test if window can be zoned by FancyZones
-struct FancyZonesFilter
-{
-    bool zonable = false; // If the window is zonable by FancyZones by default - true when both standard_window and no_visible_owner are also true
-    bool standard_window = false; // True if from the styles the window looks like a standard window
-    bool no_visible_owner = false; // True if the window is a top-level window that does not have a visible owner
-    std::wstring process_path; // Path to the executable owning the window
-};
-FancyZonesFilter get_fancyzones_filtered_window(HWND window);
-
-// Gets active foreground window, filtering out all "non standard" windows like the taskbar, etc.
-struct ShortcutGuideFilter
-{
-    HWND hwnd = nullptr; // Handle to the top-level foreground window or nullptr if there is no such window
-    bool snappable = false; // True, if the window can react to Windows Snap keys
-};
-ShortcutGuideFilter get_shortcutguide_filtered_window();
+// Check if window is part of the shell or the taskbar.
+bool is_system_window(HWND hwnd, const char* class_name);
 
 // Calculate sizes
 int width(const RECT& rect);