git: Improve co-author button (#29742)

Danilo Leal and Joseph T. Lyons created 

This PR changes the tooltip label to say "Remove" when you have the
button toggled on and collaborators in the list.

Release Notes:

- N/A

Co-authored-by: Joseph T. Lyons <josephtlyons@gmail.com>

Change summary

assets/icons/user_check.svg    |  1 +
crates/git_ui/src/git_panel.rs | 12 ++++++++++--
crates/icons/src/icons.rs      |  1 +
3 files changed, 12 insertions(+), 2 deletions(-)

Detailed changes

assets/icons/user_check.svg 🔗 

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-user-round-check-icon lucide-user-round-check"><path d="M2 21a8 8 0 0 1 13.292-6"/><circle cx="10" cy="8" r="5"/><path d="m16 19 2 2 4-4"/></svg>

crates/git_ui/src/git_panel.rs 🔗 

@@ -2755,18 +2755,26 @@ impl GitPanel {
 
     pub(crate) fn render_co_authors(&self, cx: &Context<Self>) -> Option<AnyElement> {
         let potential_co_authors = self.potential_co_authors(cx);
+
+        let (tooltip_label, icon) = if self.add_coauthors {
+            ("Add co-authored-by", IconName::UserCheck)
+        } else {
+            ("Remove co-authored-by", IconName::Person)
+        };
+
         if potential_co_authors.is_empty() {
             None
         } else {
             Some(
-                IconButton::new("co-authors", IconName::Person)
+                IconButton::new("co-authors", icon)
                     .shape(ui::IconButtonShape::Square)
                     .icon_color(Color::Disabled)
                     .selected_icon_color(Color::Selected)
                     .toggle_state(self.add_coauthors)
                     .tooltip(move |_, cx| {
                         let title = format!(
-                            "Add co-authored-by:{}{}",
+                            "{}:{}{}",
+                            tooltip_label,
                             if potential_co_authors.len() == 1 {
                                 ""
                             } else {