fix issues

- revert nullptr check for BMap::MeshTrans pointer getter.
- fix pointer return error of BMap::MeshTrans
- fix type hint error and variable name error in PyBMap
- fix CKMesh flag init value error
- improve empty material slots saving. add a nullptr entry if no slots to make sure virtools can load it.

BMapBindings/PyBMap/.gitignore

@@ -1,4 +1,5 @@
 # my ban
+.vscode/
 *.dll
 *.pdb
 *.so