Worktree paths in git panel, take 2 (#26047)

Modified version of #25950. We still use worktree paths, but repo paths
with a status that lie outside the worktree are not excluded; instead,
we relativize them by adding `..`. This makes the list in the git panel
match what you'd get from running `git status` (with the repo's worktree
root as the working directory).

- [x] Implement + test new unrelativization logic
- [x] ~~When collecting repositories, dedup by .git abs path, so
worktrees can share a repo at the project level~~ dedup repos at the
repository selector layer, with repos coming from larger worktrees being
preferred
- [x] Open single-file worktree with diff when activating a path not in
the worktree

Release Notes:

- N/A

crates/markdown_preview/src/markdown_renderer.rs

@@ -23,7 +23,7 @@ use ui::{
     LabelSize, LinkPreview, StatefulInteractiveElement, StyledExt, StyledImage, ToggleState,
     Tooltip, VisibleOnHover,
 };
-use workspace::Workspace;
+use workspace::{OpenOptions, OpenVisible, Workspace};
 
 type CheckboxClickedCallback = Arc<Box<dyn Fn(bool, Range<usize>, &mut Window, &mut App)>>;
 
@@ -490,7 +490,15 @@ fn render_markdown_text(parsed_new: &MarkdownParagraph, cx: &mut RenderContext)
                                     if let Some(workspace) = &workspace {
                                         _ = workspace.update(cx, |workspace, cx| {
                                             workspace
-                                                .open_abs_path(path.clone(), false, window, cx)
+                                                .open_abs_path(
+                                                    path.clone(),
+                                                    OpenOptions {
+                                                        visible: Some(OpenVisible::None),
+                                                        ..Default::default()
+                                                    },
+                                                    window,
+                                                    cx,
+                                                )
                                                 .detach();
                                         });
                                     }
@@ -545,7 +553,15 @@ fn render_markdown_text(parsed_new: &MarkdownParagraph, cx: &mut RenderContext)
                                         if let Some(workspace) = &workspace {
                                             _ = workspace.update(cx, |workspace, cx| {
                                                 workspace
-                                                    .open_abs_path(path.clone(), false, window, cx)
+                                                    .open_abs_path(
+                                                        path.clone(),
+                                                        OpenOptions {
+                                                            visible: Some(OpenVisible::None),
+                                                            ..Default::default()
+                                                        },
+                                                        window,
+                                                        cx,
+                                                    )
                                                     .detach();
                                             });
                                         }