extension: Update DAP extension API (#32448)

- DAP schemas will be stored in `debug_adapters_schemas` subdirectory in
extension work dir.
- Added Debug Config integration and such.

Release Notes:

- N/A

crates/dap_adapters/src/javascript.rs

@@ -182,7 +182,7 @@ impl DebugAdapter for JsDebugAdapter {
         })
     }
 
-    async fn dap_schema(&self) -> serde_json::Value {
+    fn dap_schema(&self) -> serde_json::Value {
         json!({
             "oneOf": [
                 {