Hex stays on top and thus interferes with screen sharing only a window

**Describe the bug**
A clear and concise description of what the bug is.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to any app you want to screenshare
2. Select option to share a window (not the whole screen)
3. The share this widow button is not clickable, you need to click the title bar first to bring it in focus.
4. It doesn't work at all if a window is in full screen

**Expected behavior**
I should be able to click on the share this window button when hex is running

Start by reproducing the window-sharing behavior on macOS with Hex running, including a full-screen window. Locate the code responsible for Hex's window focus or always-on-top behavior; done means the share-this-window control is clickable without refocusing the title bar and still works with a full-screen window.

Written by the indexing model from the issue text.