Add "navigation buttons" for a (horizontally) scrollable TabControl #3977
Description
Is your feature request related to a problem? Please describe.
When using the TabControl in a setting where the number of tabs may exceed the available width of the TabControl (i.e. the viewport), navigating between the tabs (especially the ones out of view) is a little cumbersome.
Describe the solution you'd like
If/when the TabControl has set of tab headers which exceed the available width, it would be nice to show 2 small "navigation buttons" allowing the user to navigate between the tabs (i.e. increasing/decreasing TabControl.SelectedIndex).
Describe alternatives you've considered
Issue #3976 touches upon the same issue, and a fix for that makes this feature request slightly less important.
Additional context
This is a small example of how I would like it to work. Disregard the '+' button, as that is simply something specific to my app. As you can see, the navigation buttons appear when there is a need for them, and they allow the user to change the selected tab in either direction. This implementation was done in the consuming application code, and I would like to see something similar added to MDIX so you can get a similar behavior out-of-the-box.
