settings: Auto-update JSON schemas for settings when extensions are un/installed (#26633)

Because of #26562, it is now possible to subscribe to extension update
events within the LSP store, where we can then update the Schemas sent
to the JSON LSP resulting in dynamic updates to the auto-complete
suggestions and diagnostics in settings. Notably, this means newly
installed languages and (icon) themes will auto-complete correctly as
soon as the extension is installed.

Closes #15436

Release Notes:

- Fixed an issue where autocomplete suggestions and diagnostics for
languages and (icon) themes in settings would not update when the
extension with which they were added was installed or uninstalled

crates/project/src/project.rs

@@ -95,6 +95,10 @@ use util::{
     ResultExt as _,
 };
 use worktree::{CreatedEntry, Snapshot, Traversal};
+pub use worktree::{
+    Entry, EntryKind, File, LocalWorktree, PathChange, ProjectEntryId, UpdatedEntriesSet,
+    UpdatedGitRepositoriesSet, Worktree, WorktreeId, WorktreeSettings, FS_WATCH_LATENCY,
+};
 use worktree_store::{WorktreeStore, WorktreeStoreEvent};
 
 pub use fs::*;
@@ -104,10 +108,6 @@ pub use prettier::FORMAT_SUFFIX as TEST_PRETTIER_FORMAT_SUFFIX;
 pub use task_inventory::{
     BasicContextProvider, ContextProviderWithTasks, Inventory, TaskContexts, TaskSourceKind,
 };
-pub use worktree::{
-    Entry, EntryKind, File, LocalWorktree, PathChange, ProjectEntryId, UpdatedEntriesSet,
-    UpdatedGitRepositoriesSet, Worktree, WorktreeId, WorktreeSettings, FS_WATCH_LATENCY,
-};
 
 pub use buffer_store::ProjectTransaction;
 pub use lsp_store::{