WM: add utility to lookup a keymap item from an event

Useful for modal operators to be able to match events
against regular keymaps.

source/blender/windowmanager/WM_api.h

@@ -243,6 +243,10 @@ void WM_event_set_keymap_handler_post_callback(struct wmEventHandler_Keymap *han
 wmKeyMap *WM_event_get_keymap_from_handler(wmWindowManager *wm,
                                            struct wmEventHandler_Keymap *handler);
 
+wmKeyMapItem *WM_event_match_keymap_item(struct bContext *C,
+                                         wmKeyMap *keymap,
+                                         const struct wmEvent *event);
+
 typedef int (*wmUIHandlerFunc)(struct bContext *C, const struct wmEvent *event, void *userdata);
 typedef void (*wmUIHandlerRemoveFunc)(struct bContext *C, void *userdata);