ClangFormat: apply to source, most of intern

Apply clang format as proposed in T53211.

For details on usage and instructions for migrating branches
without conflicts, see:

https://wiki.blender.org/wiki/Tools/ClangFormat

source/blender/freestyle/intern/python/BPy_Interface1D.h

@@ -37,20 +37,19 @@ extern "C" {
 
 extern PyTypeObject Interface1D_Type;
 
-#define BPy_Interface1D_Check(v) (PyObject_IsInstance((PyObject *)v, (PyObject *)&Interface1D_Type))
+#define BPy_Interface1D_Check(v) \
+  (PyObject_IsInstance((PyObject *)v, (PyObject *)&Interface1D_Type))
 
 /*---------------------------Python BPy_Interface1D structure definition----------*/
 typedef struct {
-	PyObject_HEAD
-	Interface1D *if1D;
-	bool borrowed; /* true if *if1D is a borrowed object */
+  PyObject_HEAD Interface1D *if1D;
+  bool borrowed; /* true if *if1D is a borrowed object */
 } BPy_Interface1D;
 
 /*---------------------------Python BPy_Interface1D visible prototypes-----------*/
 
 int Interface1D_Init(PyObject *module);
 
-
 ///////////////////////////////////////////////////////////////////////////////////////////
 
 #ifdef __cplusplus