Make TextEdit autocompletion replace word unless Shift is held

This makes Tab and Enter act identical by default for autocompletion.

If Shift is held, the suggestion is added in-place without the word
being replaced. This matches the behavior found in Visual Studio Code
where the following occurs:

- Pressing Tab accepts the suggestion and replaces the word.
- Pressing Enter accepts the suggestion and replaces the word.
- Pressing Shift + Tab accepts the suggestion and doesn't replace the word.
- Pressing Shift + Enter accepts the suggestion and doesn't replace the word.

core/input/input_map.cpp

@@ -510,12 +510,15 @@ const HashMap<String, List<Ref<InputEvent>>> &InputMap::get_builtins() {
 	default_builtin_cache.insert("ui_text_completion_query", inputs);
 
 	inputs = List<Ref<InputEvent>>();
-	inputs.push_back(InputEventKey::create_reference(Key::ENTER));
-	inputs.push_back(InputEventKey::create_reference(Key::KP_ENTER));
+	inputs.push_back(InputEventKey::create_reference(KeyModifierMask::SHIFT | Key::TAB));
+	inputs.push_back(InputEventKey::create_reference(KeyModifierMask::SHIFT | Key::ENTER));
+	inputs.push_back(InputEventKey::create_reference(KeyModifierMask::SHIFT | Key::KP_ENTER));
 	default_builtin_cache.insert("ui_text_completion_accept", inputs);
 
 	inputs = List<Ref<InputEvent>>();
 	inputs.push_back(InputEventKey::create_reference(Key::TAB));
+	inputs.push_back(InputEventKey::create_reference(Key::ENTER));
+	inputs.push_back(InputEventKey::create_reference(Key::KP_ENTER));
 	default_builtin_cache.insert("ui_text_completion_replace", inputs);
 
 	// Newlines
@@ -525,7 +528,6 @@ const HashMap<String, List<Ref<InputEvent>>> &InputMap::get_builtins() {
 	default_builtin_cache.insert("ui_text_newline", inputs);
 
 	inputs = List<Ref<InputEvent>>();
-
 	inputs.push_back(InputEventKey::create_reference(Key::ENTER | KeyModifierMask::CMD_OR_CTRL));
 	inputs.push_back(InputEventKey::create_reference(Key::KP_ENTER | KeyModifierMask::CMD_OR_CTRL));
 	default_builtin_cache.insert("ui_text_newline_blank", inputs);