[feat] Add a Tab Bar for Open Files

[devvaannsh]

Describe the problem

Right now, Phoenix Code should have a tab bar at the top which will display the list of open files. Most other editors have this, and it’s something users are used to. A simple tab bar at the top showing open files would make navigation much easier.

Describe the solution you'd like

The files in the working tree should appear as a tab.
clicking a tab should switch to that file.
there should be a close button on each tab, which when clicked will remove that file the working tree, thus removing it from tab bar
dragging tabs to reorder them would be great!

[Users should have an option to hide/disable this tab bar]

Alternatives considered

No response

Additional context

No response

[abose]

This is already tracked as part of #161 in modern UX project.
Closing as duplicate.