[tools\tlbparser.py] Import QueryPathOfRegTypeLib from typeinfo + doc adjustments

[moi15moi]

See #735

I needed to use a try except because, now, _QueryPathOfRegTypeLib return a HRESULT and not a c_int

[junkmd]

This goes beyond simply replacing windll with WinDLL and likely exceeds the scope of #735.
However, the concept behind this change is excellent as a refactoring effort, so let’s keep this PR open and continue the discussion about QueryPathOfRegTypeLib.

(This is one of the benefits of Small CLs. If there were other types of changes or modifications to other modules, this PR would have taken much longer to reach the point of merging.)

[junkmd]

If making such changes, should we now be using higher-level public functions?
QueryPathOfRegTypeLib eliminates the need to prepare a BSTR and the handling of the null terminator.

 def get_tlib_filename(tlib: typeinfo.ITypeLib) -> Optional[str]:
     # seems if the typelib is not registered, there's no way to
     # determine the filename.
     la = tlib.GetLibAttr()
-    name = BSTR()
     try:
-        _QueryPathOfRegTypeLib(
-            byref(la.guid), la.wMajorVerNum, la.wMinorVerNum, 0, byref(name)
+        full_filename = typeinfo.QueryPathOfRegTypeLib(
+            str(la.guid), la.wMajorVerNum, la.wMinorVerNum
         )
     except OSError:
         return None

-    full_filename = name.value.split("\0")[0]
     if not os.path.isabs(full_filename):
         # workaround Windows 7 bug in QueryPathOfRegTypeLib returning relative path
         try:

Since these changes exceed the scope of #735, I believe the PR title could be updated to better focus on QueryPathOfRegTypeLib.

P.S. Import part:

 import os
 import sys
-from ctypes import alignment, byref, c_void_p, sizeof, windll
+from ctypes import alignment, c_void_p, sizeof, windll
 from typing import Any, Dict, List, Optional, Tuple

-from comtypes import BSTR, COMError, automation, typeinfo
+from comtypes import COMError, automation, typeinfo
 from comtypes.client._code_cache import _get_module_filename
 from comtypes.tools import typedesc
-from comtypes.typeinfo import _QueryPathOfRegTypeLib

[moi15moi]

You right.
Now, I directly call QueryPathOfRegTypeLib from typeinfo.
I also added some documentation, so we can clearly understand that QueryPathOfRegTypeLib can raise a OSError.

[junkmd]

Thanks!