Event System: remove tweak events in favor of click-drag

Supporting two kinds of dragging is redundant, remove tweak events as
they only supported 3 mouse buttons and added complexity from using the
'value' to store directions.

Support only click-drag events (KM_CLICK_DRAG) which can be used with
any keyboard or mouse button.

Details:

- A "direction" member has been added to keymap items and events which
  can be used when the event value is set to KM_CLICK_DRAG.

- Keymap items are version patched.

- Loading older key-maps are also updated.

- Currently the key-maps stored in ./release/scripts/presets/keyconfig/
  still reference tweak events & need updating. For now they are updated
  on load.

Note that in general this wont impact add-ons as modal operators don't
receive tweak events.

Reviewed By: brecht

Ref D14214

release/scripts/modules/bl_keymap_utils/versioning.py

@@ -30,4 +30,22 @@ def keyconfig_update(keyconfig_data, keyconfig_version):
                     # Setting repeat true on other kinds of events is harmless.
                     item_event["repeat"] = True
 
+    if keyconfig_version <= (3, 2, 5):
+        # Only copy once.
+        if not has_copy:
+            keyconfig_data = copy.deepcopy(keyconfig_data)
+            has_copy = True
+
+        for _km_name, _km_parms, km_items_data in keyconfig_data:
+            for (_item_op, item_event, _item_prop) in km_items_data["items"]:
+                if ty_new := {
+                        'EVT_TWEAK_L': 'LEFTMOUSE',
+                        'EVT_TWEAK_M': 'MIDDLEMOUSE',
+                        'EVT_TWEAK_R': 'RIGHTMOUSE',
+                }.get(item_event.get("type")):
+                    item_event["type"] = ty_new
+                    if (value := item_event["value"]) != 'ANY':
+                        item_event["direction"] = value
+                    item_event["value"] = 'CLICK_DRAG'
+
     return keyconfig_data