core: rename mbgl namespace to mln (#4487)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

platform/windows/src/thread_local.cpp

@@ -10,7 +10,7 @@
 #define StorageToThreadInfo reinterpret_cast<THREAD_INFO*&>(storage)
 #define StorageToConstThreadInfo reinterpret_cast<THREAD_INFO* const&>(storage)
 
-namespace mbgl {
+namespace mln {
 namespace util {
 namespace impl {
 
@@ -59,4 +59,4 @@ void ThreadLocalBase::set(void* ptr) {
 
 } // namespace impl
 } // namespace util
-} // namespace mbgl
+} // namespace mln