Rename TextureTypeToString() to aiTextureTypeToString()

Closes: https://github.com/assimp/assimp/issues/4493

code/Common/material.cpp

@@ -46,7 +46,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <assimp/material.h>
 
 // -------------------------------------------------------------------------------
-const char *TextureTypeToString(aiTextureType in) {
+const char *aiTextureTypeToString(aiTextureType in) {
     switch (in) {
     case aiTextureType_NONE:
         return "n/a";