Add KeyContextView (#19872)

Release Notes:

- Added `cmd-shift-p debug: Open Key Context View` to help debug custom
key bindings



https://github.com/user-attachments/assets/de273c97-5b27-45aa-9ff1-f943b0ed7dfe

crates/language_tools/src/language_tools.rs

@@ -1,3 +1,4 @@
+mod key_context_view;
 mod lsp_log;
 mod syntax_tree_view;
 
@@ -12,4 +13,5 @@ pub use syntax_tree_view::{SyntaxTreeToolbarItemView, SyntaxTreeView};
 pub fn init(cx: &mut AppContext) {
     lsp_log::init(cx);
     syntax_tree_view::init(cx);
+    key_context_view::init(cx);
 }