Rename Window::mouse_position to last_mouse_position

We want to encourage people to use WindowContext::mouse_position, which
requests the position from the platform.

Co-Authored-By: Conrad Irwin <conrad@zed.dev>
8e3b23e510Nathan Sobo committed on 8/23/2023, 7:28:22 PMparent684db11
1 file changedLine totals unavailable