logging: Move GetLogCategory into Logger class

diff --git a/src/logging.cpp b/src/logging.cpp
index 0edc970d..fc6dd1b8 100644
--- a/src/logging.cpp
+++ b/src/logging.cpp
@@ -224,7 +224,7 @@ static const std::unordered_map<BCLog::LogFlags, std::string> LOG_CATEGORIES_BY_
     }(LOG_CATEGORIES_BY_STR)
 };
 
-std::optional<BCLog::LogFlags> GetLogCategory(std::string_view str)
+std::optional<BCLog::LogFlags> BCLog::Logger::GetLogCategory(std::string_view str)
 {
     if (str.empty() || str == "1" || str == "all") {
         return BCLog::ALL;
diff --git a/src/logging.h b/src/logging.h
index 9ff1c7ea..a727dc24 100644
--- a/src/logging.h
+++ b/src/logging.h
@@ -275,6 +275,9 @@ namespace BCLog {
         static std::string LogLevelToStr(BCLog::Level level);
 
         bool DefaultShrinkDebugFile() const;
+
+        //! Return log flag if str parses as a log category.
+        static std::optional<BCLog::LogFlags> GetLogCategory(std::string_view str);
     };
 } // namespace BCLog
 
@@ -286,7 +289,4 @@ static inline bool LogAcceptCategory(BCLog::LogFlags category, BCLog::Level leve
     return LogInstance().WillLogCategoryLevel(category, level);
 }
 
-/// Return log flag if str parses as a log category.
-std::optional<BCLog::LogFlags> GetLogCategory(std::string_view str);
-
 #endif // BITCOIN_LOGGING_H
diff --git a/src/test/logging_tests.cpp b/src/test/logging_tests.cpp
index 550ef85c..5595fe16 100644
--- a/src/test/logging_tests.cpp
+++ b/src/test/logging_tests.cpp
@@ -166,7 +166,7 @@ BOOST_FIXTURE_TEST_CASE(logging_LogPrintMacros_CategoryName, LogSetup)
     const auto category_names = SplitString(concatenated_category_names, ',');
     for (const auto& category_name : category_names) {
         const auto trimmed_category_name = TrimString(category_name);
-        const auto category{*Assert(GetLogCategory(trimmed_category_name))};
+        const auto category{*Assert(BCLog::Logger::GetLogCategory(trimmed_category_name))};
         expected_category_names.emplace_back(category, trimmed_category_name);
     }