fix logging: fix dynamic debug logs in templates

Previously, dynamic debug logs could not turn on or off log lines within template functions correctly.
commit_hash:3ada07ac11569b97a38e79c53070692f6d6f4430

Author: Anton3

core/src/components/minimal_server_component_list_test.cpp

@@ -51,7 +51,7 @@ constexpr std::string_view kStaticConfig = R"(
       worker_threads: 4
       task-trace:
         every: 1
-        max-context-switch-count: 50
+        max-context-switch-count: 1000
         logger: tracer
   components:
     logging:

scripts/docs/en/userver/component_system.md

@@ -4,6 +4,12 @@ A userver-based service usually consists of components. A component is a basic
 building block that encapsulates dependencies logic with configuration and
 is able to interact with other components.
 
+Each component is a singleton within a service instance, so they should only encapsulate global state,
+not per-request state. (Although *factories* for per-request objects may be appropriate.)
+Any mutable state probably needs @ref scripts/docs/en/userver/synchronization.md "synchronization".
+Built-in userver components perform synchronization internally when needed and are fully thread-safe
+unless specified otherwise.
+
 \b Example:
 
 * There is a `ClientB`, that requires initialization with some `SettingsB`

universal/src/logging/dynamic_debug.hpp

@@ -39,14 +39,15 @@ struct LogEntryContent {
 bool operator<(const LogEntryContent& x, const LogEntryContent& y) noexcept;
 bool operator==(const LogEntryContent& x, const LogEntryContent& y) noexcept;
 
-using LogEntryContentSet = bi::set<  //
-    LogEntryContent,                 //
-    bi::constant_time_size<false>,   //
-    bi::member_hook<                 //
-        LogEntryContent,             //
-        LogEntryContentHook,         //
-        &LogEntryContent::hook       //
-        >                            //
+// multiset to allow multiple logs on the same line (happens with templates).
+using LogEntryContentSet = bi::multiset<  //
+    LogEntryContent,                      //
+    bi::constant_time_size<false>,        //
+    bi::member_hook<                      //
+        LogEntryContent,                  //
+        LogEntryContentHook,              //
+        &LogEntryContent::hook            //
+        >                                 //
     >;
 
 void AddDynamicDebugLog(