Test building UMF as shared library on MacOS

Author: igchor

.github/workflows/basic.yml

@@ -332,6 +332,7 @@ jobs:
         -DUMF_BUILD_OS_MEMORY_PROVIDER=OFF
         -DUMF_BUILD_LIBUMF_POOL_SCALABLE=OFF
         -DUMF_BUILD_LIBUMF_POOL_JEMALLOC=OFF
+        -DUMF_BUILD_SHARED_LIBRARY=ON
 
     - name: Build UMF
       run: cmake --build ${{env.BUILD_DIR}} -j $(sysctl -n hw.logicalcpu)