* fix: move tab scroll buttons to remove spacing before 1st tab
* fix: always show tab scroll buttons
* fix: cleanup code, get scroll button rect for correct button
* fix: expand to full size for tabs if scroll buttons arent visible
* fix: define n as visible tabs number
* Send `mouseleft` event when the mouse leaves the window
* Call `View:on_mouse_left` when the mouse leaves the `View`
Previously `View:on_mouse_left` was called only when the mouse left the
window, and it was called on every visible `View`.
Now it gets also called when the mouse "changes" `View`, and only the
last `View` the mouse was on will receive the event.
sammyette
jgmdev
Guldoman
Jipok