Use Instantiator to create drawer actions to improve startup time

Found with qml profiler that the creation of the drawer actions took the most time. Using an Instantiator is faster and causes the binding to be evaluated less often. Before the binding inside Kirigami was evaluated 28 times and it was the thing the most time was spend on, afterwards creating the window is the most costly operation. CCBUG:429855

Before: After:

Absolute numbers are incorrect since I started the app and manually closed the window once it appeared but it is an improvement.