Adjust TintColor color token terminology (#22826)

Previously, to use a green and red shade with `TintColor` you'd need to
pass `Positive` and `Negative`, respectively. This terminology always
tripped me up, because, for example, I'd often try to use something
like:

```
Button::new("icon_color", "Negative")
      style(ButtonStyle::Tinted(TintColor::Negative))
      .color(Color::Error)
      .icon_color(Color::Error)
      .icon(IconName::Trash),
)
```

...and due to `icon_color` taking `Color::Error`, I'd always get
`TintColor` wrong at a first try, because I would, out of muscle memory,
write `TintColor::Error`, which wouldn't compile. That's exactly the
change in this PR—`TintColor` now takes `Success` and `Error` instead of
`Positive` and `Negative`, for more consistency.


Release Notes:

- N/A

crates/title_bar/src/collab.rs

@@ -381,7 +381,7 @@ impl TitleBar {
                 .style(ButtonStyle::Subtle)
                 .icon_size(IconSize::Small)
                 .toggle_state(is_muted)
-                .selected_style(ButtonStyle::Tinted(TintColor::Negative))
+                .selected_style(ButtonStyle::Tinted(TintColor::Error))
                 .on_click(move |_, cx| {
                     toggle_mute(&Default::default(), cx);
                 })
@@ -398,7 +398,7 @@ impl TitleBar {
                     },
                 )
                 .style(ButtonStyle::Subtle)
-                .selected_style(ButtonStyle::Tinted(TintColor::Negative))
+                .selected_style(ButtonStyle::Tinted(TintColor::Error))
                 .icon_size(IconSize::Small)
                 .toggle_state(is_deafened)
                 .tooltip(move |cx| {