Inline git blame (#10398)

This adds so-called "inline git blame" to the editor that, when turned
on, shows `git blame` information about the current line inline:


![screenshot-2024-04-15-11 29
35@2x](https://github.com/zed-industries/zed/assets/1185253/21cef7be-3283-4556-a9f0-cc349c4e1d75)


When the inline information is hovered, a new tooltip appears that
contains more information on the current commit:


![screenshot-2024-04-15-11 28
24@2x](https://github.com/zed-industries/zed/assets/1185253/ee128460-f6a2-48c2-a70d-e03ff90a737f)

The commit message in this tooltip is rendered as Markdown, is
scrollable and clickable.

The tooltip is now also the tooltip used in the gutter:

![screenshot-2024-04-15-11 28
51@2x](https://github.com/zed-industries/zed/assets/1185253/42be3d63-91d0-4936-8183-570e024beabe)


## Settings

1. The inline git blame information can be turned on and off via
settings:
```json
{
  "git": {
    "inline_blame": {
      "enabled": true
    }
  }
}
```
2. Optionally, a delay can be configured. When a delay is set, the
inline blame information will only show up `x milliseconds` after a
cursor movement:
```json
{
  "git": {
    "inline_blame": {
      "enabled": true,
      "delay_ms": 600
    }
  }
}
```
3. It can also be turned on/off for the current buffer with `editor:
toggle git blame inline`.

## To be done in follow-up PRs

- [ ] Add link to pull request in tooltip
- [ ] Add avatars of users if possible

## Release notes

Release Notes:

- Added inline `git blame` information the editor. It can be turned on
in the settings with `{"git": { "inline_blame": "on" } }` for every
buffer or, temporarily for the current buffer, with `editor: toggle git
blame inline`.

crates/project/src/project_settings.rs

@@ -3,7 +3,7 @@ use gpui::AppContext;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use settings::{Settings, SettingsSources};
-use std::sync::Arc;
+use std::{sync::Arc, time::Duration};
 
 #[derive(Clone, Default, Serialize, Deserialize, JsonSchema)]
 pub struct ProjectSettings {
@@ -29,6 +29,30 @@ pub struct GitSettings {
     /// Default: tracked_files
     pub git_gutter: Option<GitGutterSetting>,
     pub gutter_debounce: Option<u64>,
+    /// Whether or not to show git blame data inline in
+    /// the currently focused line.
+    ///
+    /// Default: off
+    pub inline_blame: Option<InlineBlameSettings>,
+}
+
+impl GitSettings {
+    pub fn inline_blame_enabled(&self) -> bool {
+        match self.inline_blame {
+            Some(InlineBlameSettings { enabled, .. }) => enabled,
+            _ => false,
+        }
+    }
+
+    pub fn inline_blame_delay(&self) -> Option<Duration> {
+        match self.inline_blame {
+            Some(InlineBlameSettings {
+                delay_ms: Some(delay_ms),
+                ..
+            }) if delay_ms > 0 => Some(Duration::from_millis(delay_ms)),
+            _ => None,
+        }
+    }
 }
 
 #[derive(Clone, Copy, Debug, Default, Serialize, Deserialize, JsonSchema)]
@@ -41,6 +65,21 @@ pub enum GitGutterSetting {
     Hide,
 }
 
+#[derive(Clone, Copy, Debug, Default, Serialize, Deserialize, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+pub struct InlineBlameSettings {
+    /// Whether or not to show git blame data inline in
+    /// the currently focused line.
+    ///
+    /// Default: false
+    pub enabled: bool,
+    /// Whether to only show the inline blame information
+    /// after a delay once the cursor stops moving.
+    ///
+    /// Default: 0
+    pub delay_ms: Option<u64>,
+}
+
 #[derive(Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq, JsonSchema)]
 pub struct BinarySettings {
     pub path: Option<String>,