Search terms are now highlighted when the bar opens with a selection.

This is achieved by triggering a search when the bar opens. This is slightly inefficient but cleanly updates everything that's dependent on the search and reduces code duplication.

editor/code_editor.h

@@ -110,6 +110,8 @@ protected:
 	virtual void unhandled_input(const Ref<InputEvent> &p_event) override;
 	void _focus_lost();
 
+	void _update_flags(bool p_direction_backwards);
+
 	bool _search(uint32_t p_flags, int p_from_line, int p_from_col);
 
 	void _replace();