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/python/gpu/gpu_py_offscreen.h

@@ -25,12 +25,11 @@
 
 extern PyTypeObject BPyGPUOffScreen_Type;
 
-#define BPyGPUOffScreen_Check(v)      (Py_TYPE(v) == &BPyGPUOffScreen_Type)
+#define BPyGPUOffScreen_Check(v) (Py_TYPE(v) == &BPyGPUOffScreen_Type)
 
 typedef struct BPyGPUOffScreen {
-	PyObject_HEAD
-	struct GPUOffScreen *ofs;
-	bool is_saved;
+  PyObject_HEAD struct GPUOffScreen *ofs;
+  bool is_saved;
 } BPyGPUOffScreen;
 
 PyObject *BPyGPUOffScreen_CreatePyObject(struct GPUOffScreen *ofs) ATTR_NONNULL(1);