core: rename mbgl namespace to mln (#4487)

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

test/util/rotation.test.cpp

@@ -5,7 +5,7 @@
 #include <mbgl/util/constants.hpp>
 #include <mbgl/util/interpolate.hpp>
 
-using namespace mbgl;
+using namespace mln;
 using namespace style;
 
 Rotation createRotation(double angle) {
@@ -18,6 +18,6 @@ TEST(Rotation, Calculations) {
     Rotation rot2(-42);
     EXPECT_EQ(rot2, Rotation(360 - 42));
 
-    mbgl::util::Interpolator<mbgl::style::Rotation> i;
+    mln::util::Interpolator<mln::style::Rotation> i;
     EXPECT_NEAR(i(rot, rot2, 0.5).getAngle(), 0.0, 0.00001);
 }