debugger: Add extensions support (#30625)

Closes #ISSUE

Release Notes:

- N/A

---------

Co-authored-by: Anthony <anthony@zed.dev>

crates/debug_adapter_extension/src/debug_adapter_extension.rs

@@ -0,0 +1,40 @@
+mod extension_dap_adapter;
+
+use std::sync::Arc;
+
+use dap::DapRegistry;
+use extension::{ExtensionDebugAdapterProviderProxy, ExtensionHostProxy};
+use extension_dap_adapter::ExtensionDapAdapter;
+use gpui::App;
+
+pub fn init(extension_host_proxy: Arc<ExtensionHostProxy>, cx: &mut App) {
+    let language_server_registry_proxy = DebugAdapterRegistryProxy::new(cx);
+    extension_host_proxy.register_debug_adapter_proxy(language_server_registry_proxy);
+}
+
+#[derive(Clone)]
+struct DebugAdapterRegistryProxy {
+    debug_adapter_registry: DapRegistry,
+}
+
+impl DebugAdapterRegistryProxy {
+    fn new(cx: &mut App) -> Self {
+        Self {
+            debug_adapter_registry: DapRegistry::global(cx).clone(),
+        }
+    }
+}
+
+impl ExtensionDebugAdapterProviderProxy for DebugAdapterRegistryProxy {
+    fn register_debug_adapter(
+        &self,
+        extension: Arc<dyn extension::Extension>,
+        debug_adapter_name: Arc<str>,
+    ) {
+        self.debug_adapter_registry
+            .add_adapter(Arc::new(ExtensionDapAdapter::new(
+                extension,
+                debug_adapter_name,
+            )));
+    }
+}