Settings refactor (#38367)

Co-Authored-By: Ben K <ben@zed.dev>
Co-Authored-By: Anthony <anthony@zed.dev>
Co-Authored-By: Mikayla <mikayla@zed.dev>

Release Notes:

- settings: Major internal changes to settings. The primary user-facing
effect is that some settings which did not make sense in project
settings files are no-longer read from there. (For example the inline
blame settings)

---------

Co-authored-by: Ben Kunkle <ben@zed.dev>
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
Co-authored-by: Anthony <anthony@zed.dev>

crates/languages/src/rust.rs

@@ -1051,7 +1051,6 @@ mod tests {
     use super::*;
     use crate::language;
     use gpui::{BorrowAppContext, Hsla, TestAppContext};
-    use language::language_settings::AllLanguageSettings;
     use lsp::CompletionItemLabelDetails;
     use settings::SettingsStore;
     use theme::SyntaxTheme;
@@ -1381,8 +1380,8 @@ mod tests {
             cx.set_global(test_settings);
             language::init(cx);
             cx.update_global::<SettingsStore, _>(|store, cx| {
-                store.update_user_settings::<AllLanguageSettings>(cx, |s| {
-                    s.defaults.tab_size = NonZeroU32::new(2);
+                store.update_user_settings(cx, |s| {
+                    s.project.all_languages.defaults.tab_size = NonZeroU32::new(2);
                 });
             });
         });