* Add mouse grab
We now also send mouse movement events only to the interested view.
* Add deprecation messages handler
* Make various `View`s respect `on_mouse_left`
* `StatusView`
* `TitleView`
* `TreeView`
* `ToolbarView`
* Fix scrollbar in `TreeView` not updating
We were in some cases sending outdated mouse positions to the scrollbar,
which made it think that the mouse was hovering it.
This also updates the hovered item more responsively during scroll.
* Added in double-clicking on emptyview and tab bar.
* Fixed issue with split tabs.
* Early exit if no overlapping node.
* Changed category of command to tabbar.
* Additional cleanup.
* Changed for whether we should show tabs.
* Fixed erroneous hover.
* 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.