feat(http/h2c): h2c test server with a Dockerfile

- Implemented a basic HTTP/2 server that responds with "ok" to requests.
- Updated dev.compose.yml to include a service for it

dev.compose.yml

@@ -54,6 +54,15 @@ services:
       - USERS=user:$$2a$$10$$UdLYoJ5lgPsC0RKqYH/jMua7zIn0g9kPqWmhYayJYLaZQ/FTmH2/u # user:password
     labels:
       proxy.tinyauth.port: "3000"
+  h2c_test_server:
+    build:
+      context: cmd/h2c_test_server
+      dockerfile: Dockerfile
+    container_name: h2c_test
+    restart: unless-stopped
+    labels:
+      proxy.#1.scheme: h2c
+      proxy.#1.port: 80
 configs:
   parca:
     content: |