tests: move mocks to tests/*

tests/mocks/api/github/rest/users/getByUsername.mjs

@@ -0,0 +1,18 @@
+/**Mocked data */
+export default function({faker}, target, that, [{username}]) {
+  console.debug("metrics/compute/mocks > mocking rest api result > rest.repos.getByUsername")
+  return ({
+    status:200,
+    url:`https://api.github.com/users/${username}/`,
+    headers:{
+      server:"GitHub.com",
+      status:"200 OK",
+      "x-oauth-scopes":"repo",
+    },
+    data:{
+      login:faker.internet.userName(),
+      avatar_url:null,
+      contributions:faker.datatype.number(1000),
+    },
+  })
+}