pythongh-90868: Adjust the Generated Objects (pythongh-99223)

We do the following:

* move the generated _PyUnicode_InitStaticStrings() to its own file
* move the generated _PyStaticObjects_CheckRefcnt() to its own file
* include pycore_global_objects.h in extension modules instead of pycore_runtime_init.h

These changes help us avoid including things that aren't needed.

python#90868

Author: ericsnowcurrently

.gitattributes

@@ -69,7 +69,7 @@ Doc/library/token-list.inc                          generated
 Include/internal/pycore_ast.h                       generated
 Include/internal/pycore_ast_state.h                 generated
 Include/internal/pycore_opcode.h                    generated
-Include/internal/pycore_runtime_init_generated.h    generated
+Include/internal/pycore_*_generated.h               generated
 Include/opcode.h                                    generated
 Include/token.h                                     generated
 Lib/keyword.py                                      generated