Test: New terminal scroll bar

[Tyriar]

Refs: #216521

• macOS @deepak1556
• linux @rzhao271
• windows @chrisdias

Complexity: 3

Create Issue

---

The terminal has a new scroll bar built on the one we use everywhere else! This took some pretty big changes behind the scenes in order to have xterm.js depend on part of VS Code's codebase. Please test the scroll bar, in particular check the following:

• The editor and terminal scroll bars look and behave the same
• Successful commands show up as blue in the left side of the overview ruler
• Ctrl+c or empty commands show up as grey in the left side of the overview ruler
• Failed commands show up as red in the right side of the overview ruler
• Find results show up in the middle of the overview ruler
• The overview ruler and scroll bar are pixel perfect positioned
• Smooth scroll still works as expected ("terminal.integrated.smoothScrolling": true)