Enable Screenshot & Screenshot history shortcut changing in MACOS (#2098)

* Enable Screenshot & Screenshot history shortcut changing in MACOS
From issue #1259 and my experience, I've fix and test this feature in my Hackintosh. So now you can change shortcut to take screenshot and show screenshot history (require restart flameshot).
- Default key to take screenshot is "Cmd + Shift + X", screenshot history is "Option + Shift + X".
- Added new translate text "Require restart flameshot".

* - Change message text for screenshot shortcut

* - Format code using clang-format

Co-authored-by: adrienpixodeo <adrien@pixodeo.net>