PY-47281 Exclude names from internal modules of libraries from auto-importing

Namely, names such as "numpy.random._examples.numba.extending.numbacall" or
"numpy.testing._private.noseclasses.NumpyDoctest" should no longer be suggested,
unless they are also exported in a public package higher in the hierarchy.

It doesn't not affect definitions from internal modules that belong to project
sources, these are still offered in the lookup.

GitOrigin-RevId: 2be393f30bd7d9905a31bdbe8db101807c136617

python/testData/completion/notImportedQualifiedName/VariantsFromInternalSkeletonsExcludedUnlessExported/python_stubs/mypackage/_impl.py

@@ -0,0 +1,6 @@
+def func_exported():
+    pass
+
+
+def func():
+    pass

python/testData/completion/notImportedQualifiedName/VariantsFromInternalSkeletonsExcludedUnlessExported/site-packages/mypackage/__init__.py

@@ -0,0 +1 @@
+from ._impl import func_exported

python/testData/completion/notImportedQualifiedName/VariantsFromInternalSkeletonsExcludedUnlessExported/src/main.py

@@ -0,0 +1 @@
+mypa.fu<caret>

python/testData/completion/notImportedQualifiedName/VariantsFromInternalSkeletonsExcludedUnlessExported/src/mypackage_util/_impl.py

@@ -0,0 +1,2 @@
+def func():
+    pass

python/testData/completion/notImportedQualifiedName/VariantsFromInternalThirdPartyModulesExcludedUnlessExported/site-packages/mypackage/__init__.py

@@ -0,0 +1 @@
+from ._impl import func_exported

python/testData/completion/notImportedQualifiedName/VariantsFromInternalThirdPartyModulesExcludedUnlessExported/site-packages/mypackage/_impl.py

@@ -0,0 +1,6 @@
+def func_exported():
+    pass
+
+
+def func():
+    pass

python/testData/completion/notImportedQualifiedName/VariantsFromInternalThirdPartyModulesExcludedUnlessExported/site-packages/mypackage/_vendor/lib.py

@@ -0,0 +1,2 @@
+def func():
+    pass

python/testData/completion/notImportedQualifiedName/VariantsFromInternalThirdPartyModulesExcludedUnlessExported/src/main.py

@@ -0,0 +1 @@
+mypack.fun<caret>

python/testData/completion/notImportedQualifiedName/VariantsFromInternalThirdPartyModulesExcludedUnlessExported/src/mypackage_util/_impl.py

@@ -0,0 +1,2 @@
+def func():
+    pass