open picker (#14524)

Release Notes:

- linux: Added a fallback Open picker for when XDG is not working
- Added a new setting `use_system_path_prompts` (default true) that can
be disabled to use Zed's builtin keyboard-driven prompts.

---------

Co-authored-by: Max <max@zed.dev>

crates/workspace/src/workspace_settings.rs

@@ -14,6 +14,7 @@ pub struct WorkspaceSettings {
     pub restore_on_startup: RestoreOnStartupBehaviour,
     pub drop_target_size: f32,
     pub when_closing_with_no_tabs: CloseWindowWhenNoItems,
+    pub use_system_path_prompts: bool,
 }
 
 #[derive(Copy, Clone, Default, Serialize, Deserialize, JsonSchema)]
@@ -83,6 +84,11 @@ pub struct WorkspaceSettingsContent {
     ///
     /// Default: auto ("on" on macOS, "off" otherwise)
     pub when_closing_with_no_tabs: Option<CloseWindowWhenNoItems>,
+    /// Whether to use the system provided dialogs for Open and Save As.
+    /// When set to false, Zed will use the built-in keyboard-first pickers.
+    ///
+    /// Default: true
+    pub use_system_path_prompts: Option<bool>,
 }
 
 #[derive(Deserialize)]