Investigate further actions to take to be able to show the ulauncher window faster

[friday]

Description

See #1393

Investigate if we can do more to get the window to show up faster initially.

Remaining culprits:

• Try using Cython perf: build with cython #1395
• I didn't test, but I know that loading the Gtk app with dbus etc is time we could shave off by just showing the window, but changing this to be conditional would be very hard and possibly risk introducing the focus steal prevention issue.
• Binding the hotkey to the ulauncher command directly instead of gapplication launch io.ulauncher.Ulauncher?

Communication guidelines

• I have read and agree with Ulauncher's communication guidelines and checked the existing enhancement requests before suggesting this.

Ulauncher v6

• I have checked and couldn't find my suggestion in v6.