Record more information into structured logs. (#9654)

Records additional request information into the structured logs,
e.g. the requester, IP address, etc.

tests/util/caches/test_descriptors.py

@@ -661,14 +661,13 @@ class CachedListDescriptorTestCase(unittest.TestCase):
 
             @descriptors.cachedList("fn", "args1")
             async def list_fn(self, args1, arg2):
-                assert current_context().request == "c1"
+                assert current_context().name == "c1"
                 # we want this to behave like an asynchronous function
                 await run_on_reactor()
-                assert current_context().request == "c1"
+                assert current_context().name == "c1"
                 return self.mock(args1, arg2)
 
-        with LoggingContext() as c1:
-            c1.request = "c1"
+        with LoggingContext("c1") as c1:
             obj = Cls()
             obj.mock.return_value = {10: "fish", 20: "chips"}
             d1 = obj.list_fn([10, 20], 2)