settings: Use a derive macro for refine (#38451)

When we refactored settings to not pass JSON blobs around, we ended up
needing
to write *a lot* of code that just merged things (like json merge used
to do).

Use a derive macro to prevent typos in this logic.

Release Notes:

- N/A

crates/vim/src/vim.rs

@@ -45,7 +45,6 @@ use std::{mem, ops::Range, sync::Arc};
 use surrounds::SurroundsType;
 use theme::ThemeSettings;
 use ui::{IntoElement, SharedString, px};
-use util::MergeFrom;
 use vim_mode_setting::HelixModeSetting;
 use vim_mode_setting::VimModeSetting;
 use workspace::{self, Pane, Workspace};
@@ -1845,7 +1844,7 @@ impl From<settings::ModeContent> for Mode {
 }
 
 impl Settings for VimSettings {
-    fn from_defaults(content: &settings::SettingsContent, _cx: &mut App) -> Self {
+    fn from_settings(content: &settings::SettingsContent, _cx: &mut App) -> Self {
         let vim = content.vim.clone().unwrap();
         Self {
             default_mode: vim.default_mode.unwrap().into(),
@@ -1857,29 +1856,4 @@ impl Settings for VimSettings {
             cursor_shape: vim.cursor_shape.unwrap().into(),
         }
     }
-
-    fn refine(&mut self, content: &settings::SettingsContent, _cx: &mut App) {
-        let Some(vim) = content.vim.as_ref() else {
-            return;
-        };
-        self.default_mode
-            .merge_from(&vim.default_mode.map(Into::into));
-        self.toggle_relative_line_numbers
-            .merge_from(&vim.toggle_relative_line_numbers);
-        self.use_system_clipboard
-            .merge_from(&vim.use_system_clipboard);
-        self.use_smartcase_find.merge_from(&vim.use_smartcase_find);
-        self.custom_digraphs.merge_from(&vim.custom_digraphs);
-        self.highlight_on_yank_duration
-            .merge_from(&vim.highlight_on_yank_duration);
-        self.cursor_shape
-            .merge_from(&vim.cursor_shape.map(Into::into));
-    }
-
-    fn import_from_vscode(
-        _vscode: &settings::VsCodeSettings,
-        _current: &mut settings::SettingsContent,
-    ) {
-        // TODO: translate vim extension settings
-    }
 }