[mlir][python] Audit and fix a lot of the Python pyi stubs.

* Classes that are still todo are marked with "# TODO: Auto-generated. Audit and fix."
* Those without this note have been cross-checked with C++ sources and most have been spot checked by hovering in VsCode.

Differential Revision: https://reviews.llvm.org/D114767

Author: stellaraccident

mlir/python/mlir/_mlir_libs/_mlir/__init__.pyi

@@ -1,13 +1,12 @@
 from typing import List
 
-globals: _Globals
+globals: "_Globals"
 
 class _Globals:
     dialect_search_modules: List[str]
-    def __init__(self, *args, **kwargs) -> None: ...
-    def _register_dialect_impl(self, dialect_namespace: str, dialect_class: object) -> None: ...
-    def _register_operation_impl(self, operation_name: str, operation_class: object, raw_opview_class: object) -> None: ...
+    def _register_dialect_impl(self, dialect_namespace: str, dialect_class: type) -> None: ...
+    def _register_operation_impl(self, operation_name: str, operation_class: type, raw_opview_class: type) -> None: ...
     def append_dialect_search_prefix(self, module_name: str) -> None: ...
 
-def register_dialect(dialect_class: object) -> object: ...
-def register_operation(dialect_class: object) -> object: ...
+def register_dialect(dialect_class: type) -> object: ...
+def register_operation(dialect_class: type) -> object: ...