Add support of auto folded directories (#7674)

Added support of auto collapsed directories, for example when directory
has only one directory inside we should display it as dir1/dir2 (#6935
). Please feel free to propose better solutions, as I am new in Rust

Demo:
https://streamable.com/seo3n9

Release Notes:

- Added support for auto-collapsing directories.

crates/project_panel/src/project_panel_settings.rs

@@ -20,6 +20,7 @@ pub struct ProjectPanelSettings {
     pub git_status: bool,
     pub indent_size: f32,
     pub auto_reveal_entries: bool,
+    pub auto_fold_dirs: bool,
 }
 
 #[derive(Clone, Default, Serialize, Deserialize, JsonSchema, Debug)]
@@ -54,6 +55,11 @@ pub struct ProjectPanelSettingsContent {
     ///
     /// Default: true
     pub auto_reveal_entries: Option<bool>,
+    /// Whether to fold directories automatically
+    /// when directory has only one directory inside.
+    ///
+    /// Default: true
+    pub auto_fold_dirs: Option<bool>,
 }
 
 impl Settings for ProjectPanelSettings {