Simplify `AppSwitcher` layout by avoiding the use of unordered list (required some workarounds, overriding default styling, etc).
By simplifying the layout, we're able to properly style the app tabs when active/on hover.
Here's what it looks like:
Note: Yes I realize there's an "and" in the diff title. Intentionally breaking this rule and including both the refactor and styling in the same diff since they're closely related and I think it'll be easier to review. If I were to make a second diff with the active/hover styling it would literally just be adding:
```
div.appTab:hover p,
div.appTab:hover svg,
div.activeTab p,
div.activeTab svg {
color: var(--fg);
stroke: var(--fg);
fill: var(--fg);
}
```