stop escaping errors for requests endpoint

Fixes #2674, at least the most annoying part of it.

locust/test/test_web.py

@@ -183,10 +183,17 @@ def test_failure_stats_csv(self):
         self._check_csv_headers(response.headers, "failures")
 
     def test_request_stats_with_errors(self):
-        self.stats.log_error("GET", "/", Exception("Error1337"))
+        self.stats.log_error("GET", "/", Exception("Error with special characters {'foo':'bar'}"))
         response = requests.get("http://127.0.0.1:%i/stats/requests" % self.web_port)
         self.assertEqual(200, response.status_code)
-        self.assertIn("Error1337", response.text)
+
+        # escaped, old school
+        # self.assertIn(
+        #     '"Exception("Error with special characters{'foo':'bar'}")"', response.text
+        # )
+
+        # not html escaping, leave that to the frontend
+        self.assertIn("\"Exception(\\\"Error with special characters {'foo':'bar'}\\\")", response.text)
 
     def test_reset_stats(self):
         try:

locust/web.py

@@ -395,11 +395,7 @@ def request_stats() -> Response:
             for s in chain(sort_stats(environment.runner.stats.entries), [environment.runner.stats.total]):
                 stats.append(s.to_dict())
 
-            for e in environment.runner.errors.values():
-                err_dict = e.serialize()
-                err_dict["name"] = escape(err_dict["name"])
-                err_dict["error"] = escape(err_dict["error"])
-                errors.append(err_dict)
+            errors = [e.serialize() for e in environment.runner.errors.values()]
 
             # Truncate the total number of stats and errors displayed since a large number of rows will cause the app
             # to render extremely slowly. Aggregate stats should be preserved.