feat: add http client

crates/churn/wit/world.wit

@@ -8,6 +8,13 @@ interface process {
     }
 }
 
+interface http {
+    resource client {
+        constructor();
+        get: func(url: string) -> list<u8>;
+    }
+}
+
 interface task {
     id: func() -> string;
     should-run: func() -> bool;
@@ -17,4 +24,5 @@ interface task {
 world churn {
     export task;
     import process;
+    import http;
 }